Firebase push notification in Flutter Android and IOS

Before you begin

Install and initialize the Firebase SDKs for Flutter if you haven’t already done so.

Install and initialize Firebase SDK in Flutter Android and IOS

Install the plugin

flutter pub add firebase_messaging

Receive messages in a Flutter app

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );

  final notificationSettings =
      await FirebaseMessaging.instance.requestPermission(
    alert: true,
    announcement: false,
    badge: true,
    carPlay: false,
    criticalAlert: false,
    provisional: true,
    sound: true,
  );

  print(
      'APNS User granted permission: ${notificationSettings.authorizationStatus}');

  // For apple platforms, ensure the APNS token is available before making any FCM plugin API calls
  // final apnsToken = await FirebaseMessaging.instance.getAPNSToken();
  final apnsToken = await getToken();
  debugPrint("APNS Token:  $apnsToken");
  if (apnsToken != null) {
    debugPrint("APNS Token:  $apnsToken");
    // APNS token is available, make FCM plugin API requests...
  }

  //Foreground message handling
  FirebaseMessaging.onMessage.listen((RemoteMessage message) {
    print('Got a message whilst in the foreground!');
    print('Message data: ${message.data}');

    if (message.notification != null) {
      print('Message also contained a notification: ${message.notification}');
    }
  });

  //Background message handling
  FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);

  runApp(const MainApp());
}

Future<String?> getToken() async {
  String? token = await FirebaseMessaging.instance.getToken();
  print("FCM Token: $token");
  return token;
}

//Background message handling
@pragma('vm:entry-point')
Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
  // If you're going to use other Firebase services in the background, such as Firestore,
  // make sure you call `initializeApp` before using other Firebase services.
  await Firebase.initializeApp();

  print("Handling a background message: ${message.messageId}");
}

Send a test notification message

1. Install and run the app on the target device. On Apple devices, you’ll need to accept the request for permission to receive remote notifications.
2. Make sure the app is in the background on the device.
3. In the Firebase console, open the Messaging page.
4. If this is your first message, select Create your first campaign.
   1. Select Firebase Notification messages and select Create.
5. Otherwise, on the Campaigns tab, select New campaign and then Notifications.
6. Enter the message text. All other fields are optional.
7. Select Send test message from the right pane.
8. In the field labeled Add an FCM registration token, enter the registration token you obtained in a previous section of this guide.
9. Select Test.