Why there is showing only one document in firebase firestore when extracting on flutter app?

[Abderrezak-douba]

signup function

 void signUp(String email, String password)  async{
    if (_formkey.currentState!.validate()) {
    await  _auth
          .createUserWithEmailAndPassword(email: email, password: password)
          .then((value) => {postDetailsToFirestore()})
          .catchError((er) {
        Fluttertoast.showToast(msg: er!.message);
      });
    }
  }

  postDetailsToFirestore() async {
    // calling our firestore
    // calling our user model
    // sending these values
    FirebaseFirestore firebaseFirestore = FirebaseFirestore.instance;
    User? user = _auth.currentUser;
    UserModel userModel = UserModel();
    // // writing all the values
    userModel.email = user!.email;
    userModel.uid = user.uid;
    userModel.username = usernameEditorcontroller.text;
    
    

    await firebaseFirestore
        .collection("users")
        .doc(user.uid)
        .set(userModel.toMap());
    Fluttertoast.showToast(msg: "account Created successfully");
    Navigator.pushAndRemoveUntil((context),
        MaterialPageRoute(builder: (context) => BottomBar()), (route) => false);
  }
}

userModel

import 'package:flutter/foundation.dart';

class UserModel {
  String? uid;
  String? username;
  String? email;
  String? photoUrl;
  

  UserModel(
      {this.uid, this.email, this.username,  this.photoUrl});

  // receving data from the server
  factory UserModel.fromMap(map) {
    return UserModel(
      uid: map['uid'],
      username: map['username'],
      email: map['email'],
      photoUrl: map['photoUrl'],
    );
  }

  // /// sending data to firestore
  Map<String, dynamic> toMap() {
    return {
      'uid': uid,
      'username': username,
      'email': email,
      'photoUrl': photoUrl,
    };
  }
}

am trying to send user information to firestore database.

[Abderrezak-douba]

@backslashflutter i did same steps as you in the tutorial but still don't work

[backslashflutter]

the screenshot that you attached above is the output from flutter code? Or you have created the database structure.

[Abderrezak-douba]

yeah but the other user id not showing in the database like in your video for some reason

[Abderrezak-douba]

and too receiving data from the database causing problem i think due to this issue i still have many other problems for example when i call username it shows null for much time and it turn to username