I do not receive custom push notifications when the application is closed

[experimentosconai]

I have tried many times, so finally I want to come to you to find the solution to show the notification when the application is closed, as proof in mainpage.dart there is a Notifications icon, after clicking that icon it is notified in 5 seconds.

• The notification appears in the foreground
• The notification appears in the background
• The notification does not appear when the application is terminated

Within the logic of the icon there are 2 conditions, if the application status is active, the local notification is shown. Otherwise a push notification would be used using the function that comes in fcm_helper.dart.

• I have looked for many solutions to show notifications, so I tried activating autostart or special permissions (autostart in the background), I gave that permission to my application and I had to restart. There are notifications, but that would not be a good practice for the user experience. That's why I want to look for the solution.
• Using Visual Studio Code.
• Using USB physical cellular Xiaomi, Samsung

Attached mainpage.dart, fcm_helper.dart, Manifest, Gradle, main.dart

mainpage.dart:
`import 'package:chatgpt_project/src/fcm/fcm_helper.dart';
//import 'package:chatgpt_project/src/notifications/fcm_schedule_notifications.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';

import 'package:firebase_auth/firebase_auth.dart';
import 'package:chatgpt_project/src/authentication/auth_google.dart';
import 'package:chatgpt_project/src/routes/routes.dart';
import 'package:chatgpt_project/src/utils/constants.dart';
import 'package:chatgpt_project/src/views/calendario.dart';
import 'package:chatgpt_project/src/views/inicio.dart';
import 'package:chatgpt_project/src/views/mas.dart';
import 'package:chatgpt_project/src/views/mi_salud.dart';
import 'package:chatgpt_project/src/firestore/user_model.dart';

import 'package:chatgpt_project/src/notifications/schedule_notifications.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:timezone/timezone.dart' as tz;

class MainPage extends StatefulWidget {
final int initialIndex;
const MainPage({Key? key, this.initialIndex = 0}) : super(key: key);

@OverRide
_MainPageState createState() => _MainPageState();
}

class _MainPageState extends State with WidgetsBindingObserver {
final FirebaseAuth _auth = FirebaseAuth.instance;
UserModel? currentUser;
// 1. Inicialización del plugin de notificaciones locales
// final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
// FlutterLocalNotificationsPlugin();

int selectedIndex =
0; // Indice para controlar la navegación en la barra inferior

Future _signOut() async {
await signOutGoogle();
await _auth.signOut();
// ignore: use_build_context_synchronously
Navigator.pushNamedAndRemoveUntil(
context,
Routes.login,
(route) => false,
);
}

void _createNotificationChannel() {
const AndroidNotificationChannel channel = AndroidNotificationChannel(
'high_priority_channel', // id
'High Priority Notifications', // title
description: 'This channel is used for important notifications.',
importance: Importance.high,
playSound: true,
);

final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
    FlutterLocalNotificationsPlugin();

flutterLocalNotificationsPlugin
    .resolvePlatformSpecificImplementation<
        AndroidFlutterLocalNotificationsPlugin>()
    ?.createNotificationChannel(channel);

}

void _sendLocalNotification(tz.TZDateTime scheduledDate) async {
const AndroidNotificationDetails androidPlatformChannelSpecifics =
AndroidNotificationDetails(
'high_priority_channel', // id
'High Priority Notifications', // title
importance: Importance.high,
priority: Priority.high,
showWhen: false,
playSound: true,
);

const NotificationDetails platformChannelSpecifics =
    NotificationDetails(android: androidPlatformChannelSpecifics);

final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
    FlutterLocalNotificationsPlugin();

await flutterLocalNotificationsPlugin.zonedSchedule(
  0, // ID de notificación
  'Titulo Local',
  'Esta es la descripción de la notificación local',
  scheduledDate,
  platformChannelSpecifics,
  androidAllowWhileIdle: true,
  uiLocalNotificationDateInterpretation:
      UILocalNotificationDateInterpretation.absoluteTime,
);

}

@OverRide
void initState() {
super.initState();

WidgetsBinding.instance.addObserver(this);
_createNotificationChannel();
_requestNotificationPermissions();
_getCurrentUser();
selectedIndex = widget.initialIndex;

}

@OverRide
void dispose() {
WidgetsBinding.instance.removeObserver(this);
super.dispose();
}

@OverRide
void didChangeAppLifecycleState(AppLifecycleState state) {
super.didChangeAppLifecycleState(state);
// Aquí puedes manejar los cambios de estado si es necesario
}

void _requestNotificationPermissions() {
FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
FlutterLocalNotificationsPlugin();

flutterLocalNotificationsPlugin
    .resolvePlatformSpecificImplementation<
        AndroidFlutterLocalNotificationsPlugin>()
    ?.requestPermission();

}

Future _getCurrentUser() async {
final firebaseUser = _auth.currentUser;
if (firebaseUser != null) {
final userDoc = await FirebaseFirestore.instance
.collection('users')
.doc(firebaseUser.uid)
.get();
setState(() {
currentUser = UserModel.fromFirestore(userDoc);
});
// Llamada a fetchMedicines
fetchMedicines(firebaseUser.uid);
}
}

@OverRide
Widget build(BuildContext context) {
final screens = [
if (currentUser != null)
InicioView(user: currentUser!), //aquí pasamos el usuario
const CalendarioView(),
if (currentUser != null)
MiSaludView(
user:
currentUser!), //user: currentUser! sirve para conectar con mi_salud.dart
const MasView()
];

return Scaffold(
  backgroundColor: scaffoldBackgroundColor,
  appBar: AppBar(
    title: const Icon(
      Icons.account_circle,
      color: Colors.white,
      size: 40.0,
    ),
    centerTitle: true,
    backgroundColor: kTextColor,
    elevation: 0,
    automaticallyImplyLeading: true, // Hacer que muestre el botón del menú
    actions: <Widget>[
      Padding(
        padding: const EdgeInsets.only(right: 9.0),
        child: IconButton(
          icon: const Icon(Icons.notifications,
              color: Colors.white, size: 33.0),
          onPressed: () async {
            AppLifecycleState? currentState =
                WidgetsBinding.instance.lifecycleState;
            try {
              if (currentState == AppLifecycleState.resumed ||
                  currentState == AppLifecycleState.inactive) {
                // La aplicación está en primer plano o en segundo plano. Envía notificación local.
                tz.TZDateTime scheduledDate = tz.TZDateTime.now(tz.local)
                    .add(const Duration(seconds: 5));
                _sendLocalNotification(scheduledDate);
                print('Notificación local programada.');
              } else if (currentState == AppLifecycleState.detached) {
                // La aplicación está completamente cerrada. Envía notificación push.
                String? currentUserId =
                    FirebaseAuth.instance.currentUser?.uid;
                if (currentUserId != null) {
                  DocumentSnapshot userDoc = await FirebaseFirestore
                      .instance
                      .collection('users')
                      .doc(currentUserId)
                      .get();
                  String? token =
                      (userDoc.data() as Map<String, dynamic>)['fcmToken'];
                  if (token != null) {
                    print('Preparando para enviar notificación push...');
                    await sendPushNotification(
                        token,
                        'Notificación de prueba',
                        'Esta es una notificación de prueba');
                    print('Notificación push enviada exitosamente.');
                  } else {
                    print('No se pudo obtener el token FCM.');
                  }
                } else {
                  print('No hay usuario autenticado.');
                }
              }
            } catch (e) {
              print("Error al intentar enviar notificación: $e");
            }
          },
        ),
      ),
    ],
  ),
  drawer: Drawer(
    child: ListView(
      padding: EdgeInsets.zero,
      children: <Widget>[
        const DrawerHeader(
          decoration: BoxDecoration(
            color: kTextColor,
          ),
          child: Text(
            'Menu',
            style: TextStyle(
              color: Colors.white,
              fontSize: 24,
            ),
          ),
        ),
        ListTile(
          leading: const Icon(Icons.logout),
          title: const Text('Cerrar sesión'),
          onTap: _signOut,
        ),
      ],
    ),
  ),
  body: IndexedStack(
    index: selectedIndex,
    children: screens,
  ),
  bottomNavigationBar: BottomNavigationBar(
    currentIndex: selectedIndex,
    onTap: (index) {
      // Solo actualiza el estado si el índice es diferente
      setState(() {
        selectedIndex = index;
      });
    },
    items: const [
      BottomNavigationBarItem(
        icon: Icon(Icons.home_outlined),
        activeIcon: Icon(Icons.home), //cambia de icono al seleccionar
        label: 'Inicio',
        backgroundColor: kTextColor,
      ),
      BottomNavigationBarItem(
        icon: Icon(Icons.calendar_month_outlined),
        activeIcon: Icon(Icons.calendar_month),
        label: 'Calendario',
        backgroundColor: kTextColor,
      ),
      BottomNavigationBarItem(
        icon: Icon(Icons.monitor_heart),
        activeIcon: Icon(Icons.monitor_heart),
        label: 'Mi Salud',
        backgroundColor: kTextColor,
      ),
      BottomNavigationBarItem(
        icon: Icon(Icons.more_horiz_outlined),
        activeIcon: Icon(Icons.more_horiz),
        label: 'Más',
        backgroundColor: kTextColor,
      ),
    ],
  ),
);

}
}
`

fcm_helper.dart:
`Future getAccessToken() async {
try {
final client = http.Client();
final AccessCredentials credentials =
await obtainAccessCredentialsViaServiceAccount(_credentials,
['https://www.googleapis.com/auth/firebase.messaging'], client);

final accessToken = credentials.accessToken.data;
client.close();
return accessToken;

} catch (e) {
print("Error obteniendo el token de acceso: $e");
throw e;
}
}

Future sendPushNotification(
String token, String title, String body) async {
try {
const String sendUrl =
'https://fcm.googleapis.com/v1/projects/proyecto-chatgpt-84b99/messages:send';
final String accessToken = await getAccessToken();

final response = await http.post(
  Uri.parse(sendUrl),
  headers: {
    'Authorization': 'Bearer $accessToken',
    'Content-Type': 'application/json',
  },
  body: json.encode({
    'message': {
      'token': token,
      'notification': {
        'title': title,
        'body': body,
      },
      'android': {
        'priority': 'high',
      },
    },
  }),
);

if (response.statusCode != 200) {
  throw Exception('Failed to send notification: ${response.body}');
}

} catch (e) {
print("Error sending the notification: $e");
throw e;
}
}`

AndroidManifest.xml:
`

    <receiver android:name=".BootCompletedReceiver" android:exported="false">
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED" />
        </intent-filter>
    </receiver>
    <!-- BootReceiver to handle re-scheduling notifications after device reboot -->
    <receiver android:name=".BootReceiver" android:enabled="true" android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED"/>
            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </receiver>

    <!-- Configuración para el canal de notificaciones de Firebase -->
    <meta-data
    android:name="com.google.firebase.messaging.default_notification_channel_id"
    android:value="high_priority_channel" />
</application>

`

build.gradle:
`def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
localPropertiesFile.withReader('UTF-8') { reader ->
localProperties.load(reader)
}
}

def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
throw GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}

def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
flutterVersionCode = '1'
}

def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
flutterVersionName = '1.0'
}

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"

android {
compileSdkVersion 33
//compileSdkVersion flutter.compileSdkVersion
ndkVersion flutter.ndkVersion

compileOptions {
    // Flag to enable support for the new language APIs
    coreLibraryDesugaringEnabled true
    // Sets Java compatibility to Java 8
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

kotlinOptions {
    jvmTarget = '1.8'
}

sourceSets {
    main.java.srcDirs += 'src/main/kotlin'
}

defaultConfig {
    // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
    applicationId "com.example.chatgpt_project"
    // You can update the following values to match your application needs.
    // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-gradle-build-configuration.
    minSdkVersion 21
    targetSdkVersion 33
    versionCode flutterVersionCode.toInteger()
    versionName flutterVersionName
    multiDexEnabled true
}

buildTypes {
    release {
        // TODO: Add your own signing config for the release build.
        // Signing with the debug keys for now, so `flutter run --release` works.
        signingConfig signingConfigs.debug
    }
}

lintOptions {
    disable 'InvalidPackage'
    disable "Instantiatable"
    checkReleaseBuilds false
    abortOnError false
}

}

flutter {
source '../..'
}

dependencies {
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
implementation 'com.android.support:multidex:2.0.1'
coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.1.5'
implementation "androidx.window:window:1.0.0"
implementation "androidx.window:window-java:1.0.0"
}

main.dart:
import 'dart:ui';

import 'package:chatgpt_project/src/authentication/auth_google.dart';
//import 'package:chatgpt_project/src/fcm/fcm_helper.dart';
import 'package:chatgpt_project/src/notifications/schedule_notifications.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';

import 'package:firebase_messaging/firebase_messaging.dart';

import 'package:chatgpt_project/src/routes/routes.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'firebase_options.dart';
//import 'package:firebase_analytics/firebase_analytics.dart';
import 'package:intl/date_symbol_data_local.dart';
import 'package:provider/provider.dart';
import 'package:chatgpt_project/src/providers/chats_provider.dart';
import 'package:firebase_auth/firebase_auth.dart';

//import 'package:chatgpt_project/src/providers/models_provider.dart';
//import 'package:flutter_dotenv/flutter_dotenv.dart';
import 'package:timezone/data/latest.dart' as tz;
import 'package:timezone/timezone.dart' as tz;
import 'package:flutter/services.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:flutter_native_timezone/flutter_native_timezone.dart';

final FirebaseFirestore _firestore = FirebaseFirestore.instance;

Future firebaseMessagingBackgroundHandler(RemoteMessage message) async {
print('Mensaje recibido en segundo plano: ${message.messageId}');

const AndroidNotificationDetails androidPlatformChannelSpecifics =
AndroidNotificationDetails(
'high_priority_channel', // id
'High Priority Notifications', // title
importance: Importance.max,
priority: Priority.high,
showWhen: false,
);

const NotificationDetails platformChannelSpecifics =
NotificationDetails(android: androidPlatformChannelSpecifics);

await FlutterLocalNotificationsPlugin().show(
0, // ID de notificación
'Titulo Prueba',
'Esta es la descripcion Prueba',
platformChannelSpecifics,
payload: 'Default_Sound',
);
}

void main() async {
WidgetsFlutterBinding.ensureInitialized();
tz.initializeTimeZones();

final String timeZoneName = await FlutterNativeTimezone.getLocalTimezone();
tz.setLocalLocation(tz.getLocation(timeZoneName));

FirebaseMessaging.onBackgroundMessage(firebaseMessagingBackgroundHandler);

await Firebase.initializeApp(
options: DefaultFirebaseOptions.currentPlatform,
);

await initializeDateFormatting('es_ES', null);

_configureFirebaseListeners();

final CallbackHandle callback =
PluginUtilities.getCallbackHandle(callbackDispatcher)!;
final int callbackHandle = callback.toRawHandle();
final SharedPreferences prefs = await SharedPreferences.getInstance();
await prefs.setInt('callback_handle', callbackHandle);

runApp(
MultiProvider(
providers: [
ChangeNotifierProvider(create: (context) => ChatProvider()),
],
child: const MyApp(),
),
);
}

Future updateTokenToFirestore(String token) async {
// Obtiene el userId del usuario autenticado
String? currentUserId = FirebaseAuth.instance.currentUser?.uid;

if (currentUserId != null) {
final docRef = _firestore.collection('users').doc(currentUserId);
final docSnapshot = await docRef.get();

if (docSnapshot.exists) {
  await docRef.update({'fcmToken': token});
} else {
  // Considera la posibilidad de crear un nuevo documento si no existe.
  // Puedes agregar más campos si es necesario.
  await docRef.set({
    'fcmToken': token,
    // 'otrosCampos': 'otrosValores',
  });
}

}
}

void _configureFirebaseListeners() async {
final FirebaseMessaging _firebaseMessaging = FirebaseMessaging.instance;

// Obtener y manejar el token de FCM
_firebaseMessaging.getToken().then((String? token) {
assert(token != null);
print("Token de FCM: $token");
updateTokenToFirestore(token!);
});

// Escuchar cambios en el token
_firebaseMessaging.onTokenRefresh.listen((String token) {
print("Token de FCM actualizado: $token");
updateTokenToFirestore(token);
});

_firebaseMessaging.getInitialMessage().then((RemoteMessage? message) {
if (message != null) {
}
});

FirebaseMessaging.onMessage.listen((RemoteMessage message) {
});

FirebaseMessaging.onMessageOpenedApp.listen((RemoteMessage message) {
});
}

void fetchMedicinesFromBoot(List args) async {
// Aquí puedes invocar fetchMedicines con el userId que necesites.
String? userId =
await getUserId(); // Aquí deberías implementar la función getUserId si aún no lo has hecho.
if (userId != null) {
fetchMedicines(userId);
}
}

void callbackDispatcher() {
const MethodChannel _backgroundChannel =
MethodChannel('com.example.chatgpt_project/background_channel');
WidgetsFlutterBinding.ensureInitialized();

_backgroundChannel.setMethodCallHandler((MethodCall call) async {
if (call.method == 'fetchMedicinesFromBoot') {
fetchMedicinesFromBoot([]);
}
});
}

class MyApp extends StatelessWidget {
const MyApp({Key? key})
: super(
key:
key); //CON ANALYTICS: const MyApp({Key? key, required this.analytics}) : super(key: key);

@OverRide
Widget build(BuildContext context) {
return MaterialApp(
title: 'My App',
debugShowCheckedModeBanner: false,
initialRoute: Routes.loading,
routes: Routes.routes,
);
}
}`

flutter doctor -v
`[√] Flutter (Channel stable, 3.13.6, on Microsoft Windows [Versi¢n 10.0.19045.3448], locale es-PE)
• Flutter version 3.13.6 on channel stable at C:\src\flutter
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision ead455963c (2 weeks ago), 2023-09-26 18:28:17 -0700
• Engine revision a794cf2681
• Dart version 3.1.3
• DevTools version 2.25.0

[√] Windows Version (Installed version of Windows is version 10 or higher)

[√] Android toolchain - develop for Android devices (Android SDK version 33.0.2)
• Android SDK at C:\Users\User\AppData\Local\Android\sdk
• Platform android-33-ext5, build-tools 33.0.2
• Java binary at: C:\Program Files\Android\Android Studio\jbr\bin\java
• Java version OpenJDK Runtime Environment (build 11.0.15+0-b2043.56-9505619)
• All Android licenses accepted.

[√] Chrome - develop for the web
• Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop Windows apps (Visual Studio Build Tools 2022 17.5.3)
• Visual Studio at C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools
• Visual Studio Build Tools 2022 version 17.5.33516.290
• Windows 10 SDK version 10.0.22621.0

[√] Android Studio (version 2022.1)
• Android Studio at C:\Program Files\Android\Android Studio
• Flutter plugin can be installed from:
https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 11.0.15+0-b2043.56-9505619)

[√] VS Code (version 1.83.0)
• VS Code at C:\Users\User\AppData\Local\Programs\Microsoft VS Code
• Flutter extension version 3.74.0

[√] Connected device (4 available)
• sdk gphone64 x86 64 (mobile) • emulator-5554 • android-x64 • Android 13 (API 33) (emulator)
• Windows (desktop) • windows • windows-x64 • Microsoft Windows [Versi¢n 10.0.19045.3448]
• Chrome (web) • chrome • web-javascript • Google Chrome 117.0.5938.150
• Edge (web) • edge • web-javascript • Microsoft Edge 117.0.2045.60

[√] Network resources
• All expected network resources are available.

• No issues found!`

[experimentosconai]

AndroidManifest.xml:

        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>

    <meta-data
        android:name="flutterEmbedding"
        android:value="2" />

    <receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver" android:exported="false">

        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED"></action>
            <action android:name="android.intent.action.MY_PACKAGE_REPLACED"></action>
        </intent-filter>

    </receiver>
    <receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationReceiver" android:exported="false" />
    <receiver android:name=".BootCompletedReceiver" android:exported="false">
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED" />
        </intent-filter>
    </receiver>
    <receiver android:name=".BootReceiver" android:enabled="true" android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED"/>
            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </receiver>
    <meta-data
    android:name="com.google.firebase.messaging.default_notification_channel_id"
    android:value="high_priority_channel" />
</application>

[pelumibabs]

Did you tried it with debug, or release mode? I experienced the same when I started my app in Debug mode.

[experimentosconai]

I am using flutter run --release, notifications do not work until I press the Autostart or sbackground permission to the application and I must restart to apply those changes, can you review my missing code?
I have used flutter notification local and push notification,