1. Both ios and AOS receive background notification normally.
2. In AOS, received background notification data can be stored in Hive through backgroundHandler.
3. But in ios BackgroundHander doesn t work.
4. If BackgroundHandler is not supported on iOS, is there another way?
5. Is it not possible to save background notification data to Hive in iOS?

@pragma( vm:entry-point )
Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );
  if (!Hive.isAdapterRegistered(1)) {
    Hive.registerAdapter<PushNotificationModel>(PushNotificationModelAdapter());
  }

  final documentDirectory = await getApplicationDocumentsDirectory();
  Hive.init(documentDirectory.path);
  if (Hive.isBoxOpen(HiveBoxConstant.BACKGROUND_NOTIFICATION_LIST)) {
    await Hive.box<PushNotificationModel>(HiveBoxConstant.BACKGROUND_NOTIFICATION_LIST).close();
  }
  if (Hive.isBoxOpen(HiveBoxConstant.NOTIFICATION_LIST)) {
    await Hive.box<PushNotificationModel>(HiveBoxConstant.NOTIFICATION_LIST).close();
  }
  await Hive.openBox<PushNotificationModel>(HiveBoxConstant.BACKGROUND_NOTIFICATION_LIST);
  await Hive.openBox<PushNotificationModel>(HiveBoxConstant.NOTIFICATION_LIST);

  await FCMManager.saveNotificationList(message, true);

  if (Hive.isBoxOpen(HiveBoxConstant.BACKGROUND_NOTIFICATION_LIST)) {
    await Hive.box<PushNotificationModel>(HiveBoxConstant.BACKGROUND_NOTIFICATION_LIST).close();
  }
  if (Hive.isBoxOpen(HiveBoxConstant.NOTIFICATION_LIST)) {
    await Hive.box<PushNotificationModel>(HiveBoxConstant.NOTIFICATION_LIST).close();
  }
}

void main() async {
  WidgetsBinding widgetsBinding = WidgetsFlutterBinding.ensureInitialized();

...

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


  runApp(
  ...
  );
}

final GlobalKey<NavigatorState> navigatorStateGlobalKey = GlobalKey<NavigatorState>();

class AppMain extends ConsumerStatefulWidget {
  const AppMain({Key? key}) : super(key: key);

  @override
  ConsumerState<AppMain> createState() => _AppMainState();
}

class _AppMainState extends ConsumerState<AppMain> with WidgetsBindingObserver {


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

    FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);

  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      ...
    );
  }

}