[firebase_auth] Where flutterfire store my token?

[polRk]

If my user want to use my app offline very long time, more than 1 year (My app support offline), can I use something like this? Or I should save token in flutter_secure_storage?

_auth.authStateChanges().listen((firebaseUser) async {
      if (firebaseUser != null) {
        token = await firebaseUser.getIdToken();
      } else {
        token = null;
      }
    });