Ready Made Code for Firebase Push Notification

import 'package:flutter/material.dart';
import 'package:dhakarchaka/pages/NextScreen.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';

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

final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
FlutterLocalNotificationsPlugin();

Future
   
     _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
  await Firebase.initializeApp();
  print('A bg message just showed up :  ${message.messageId}');
}


Future
    
      main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);
  SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp,DeviceOrientation.portraitDown]);


  await flutterLocalNotificationsPlugin
      .resolvePlatformSpecificImplementation
     
      ()
      ?.createNotificationChannel(channel);

  await FirebaseMessaging.instance.setForegroundNotificationPresentationOptions(
    alert: true,
    badge: true,
    sound: true,
  );
  runApp(MyApp());
}

class MyApp extends StatefulWidget {
  @override
  State
      
        createState() => _MyAppState();
}

class _MyAppState extends State
       
         { int _counter = 0; @override void initState() { super.initState(); FirebaseMessaging.onMessage.listen((RemoteMessage message) { RemoteNotification? notification = message.notification; AndroidNotification? android = message.notification?.android; if (notification != null && android != null) { flutterLocalNotificationsPlugin.show( notification.hashCode, notification.title, notification.body, NotificationDetails( android: AndroidNotificationDetails( channel.id, channel.name, color: Colors.blue, playSound: true, icon: '@mipmap/ic_launcher', ), )); } }); FirebaseMessaging.onMessageOpenedApp.listen((RemoteMessage message) { print('A new onMessageOpenedApp event was published!'); RemoteNotification? notification = message.notification; AndroidNotification? android = message.notification?.android; if (notification != null && android != null) { showDialog( context: context, builder: (_) { return AlertDialog( title: Text(notification.title.toString()), content: SingleChildScrollView( child: Column( crossAxisAlignment: CrossAxisAlignment.start, children: [Text(notification.body.toString())], ), ), ); }); } }); } void showNotification() { setState(() { _counter++; }); flutterLocalNotificationsPlugin.show( 0, "Testing $_counter", "How you doin ?", NotificationDetails( android: AndroidNotificationDetails(channel.id, channel.name, importance: Importance.high, color: Colors.blue, playSound: true, icon: '@mipmap/ic_launcher'))); } @override Widget build(BuildContext context) { return MaterialApp( home: NextScreen() ); } }