Firebase notification sound not working flutter

Question

I'm sending notification to my flutter app through firebase, and notification is shown on the app both when in foreground and in background, but there is no sound on either. Here's the dart file, android manifest and kotlin file I worked on to get notifications to show.

I've tried reinstalling multiple times, tried different emulators and different API levels. It's persisstant. Currently trying on API 30, and the problem still occurs. No errors when I specify channel name through firebase.

AndroidManifest:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.housekeeping_prototype">
    <application
        android:name=".Application"
        android:label="housekeeping_prototype"
        android:icon="@mipmap/ic_launcher"
        android:usesCleartextTraffic="true">
        <activity
            android:name=".MainActivity"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">
            <!-- Specifies an Android theme to apply to this Activity as soon as
                 the Android process has started. This theme is visible to the user
                 while the Flutter UI initializes. After that, this theme continues
                 to determine the Window background behind the Flutter UI. -->
            <meta-data
                android:name="io.flutter.embedding.android.NormalTheme"
                android:resource="@style/NormalTheme"
                />
            <!-- Displays an Android View that continues showing the launch screen
                 Drawable until Flutter paints its first frame, then this splash
                 screen fades out. A splash screen is useful to avoid any visual
                 gap between the end of Android's launch screen and the painting of
                 Flutter's first frame. -->
            <meta-data
                android:name="io.flutter.embedding.android.SplashScreenDrawable"
                android:resource="@drawable/launch_background"
                />
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>

            <intent-filter>
                <action android:name="FLUTTER_NOTIFICATION_CLICK"/>
                <category android:name="android.intent.category.DEFAULT"/>
            </intent-filter>

        </activity>
        <!-- Don't delete the meta-data below.
             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
        <meta-data
            android:name="flutterEmbedding"
            android:value="2" />
        <meta-data
            android:name="com.google.firebase.messaging.default_notification_channel_id"
            android:value="high_importance_channel"/>
    </application>
</manifest>

Dart:

import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:flutter/material.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:housekeeping_prototype/services/authentication_service.dart';
import 'package:housekeeping_prototype/ui/new_login_page.dart';
import 'package:housekeeping_prototype/ui/room_list.dart';
import 'package:provider/provider.dart';

Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
  await Firebase.initializeApp();
  print('Handling a background message ${message.messageId}');
}

/// Create a [AndroidNotificationChannel] for heads up notifications
const AndroidNotificationChannel channel = AndroidNotificationChannel(
  'high_importance_channel', // id
  'High Importance Notifications', // title
  'This channel is used for important notifications.', // description
  importance: Importance.high,
);

/// Initialize the [FlutterLocalNotificationsPlugin] package.
final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
    FlutterLocalNotificationsPlugin();

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();

  FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);
  await flutterLocalNotificationsPlugin
      .resolvePlatformSpecificImplementation<
          AndroidFlutterLocalNotificationsPlugin>()
      ?.createNotificationChannel(channel);

  runApp(MyApp());
}

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

class _MyAppState extends State<MyApp> {
  @override
  initState() {
    super.initState();
    var initialzationSettingsAndroid =
        AndroidInitializationSettings('@mipmap/ic_launcher');
    var initializationSettings =
        InitializationSettings(android: initialzationSettingsAndroid);

    flutterLocalNotificationsPlugin.initialize(initializationSettings);

    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,
                channel.description,
                icon: android?.smallIcon,
              ),
            ));
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return MultiProvider(
      providers: [
        Provider<AuthenticationService>(
          create: (_) => AuthenticationService(FirebaseAuth.instance),
        ),
        StreamProvider(
          create: (context) =>
              context.read<AuthenticationService>().authStateChanges,
        )
      ],
      child: MaterialApp(
        title: 'Flutter Demo',
        theme: ThemeData(
          primarySwatch: Colors.lightBlue,
        ),
        //home: RoomList(),
        //home:NewLoginPage(),
        home: AuthenticationWrapper(),
      ),
    );
  }
}

class AuthenticationWrapper extends StatelessWidget {
  const AuthenticationWrapper({
    Key key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final firebaseUser = context.watch<User>();

    if (firebaseUser != null) {
      return RoomList();
    }
    return NewLoginPage();
  }
}

Kotlin:

package com.example.housekeeping_prototype

import io.flutter.app.FlutterApplication
import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback
import io.flutter.view.FlutterMain
import io.flutter.plugins.firebase.messaging.FlutterFirebaseMessagingBackgroundService;

class Application : FlutterApplication(), PluginRegistrantCallback {

    override fun onCreate() {
        super.onCreate()
        FlutterFirebaseMessagingBackgroundService.setPluginRegistrant(this);
        FlutterMain.startInitialization(this)
    }

    override fun registerWith(registry: PluginRegistry?) {

    }
}

Answer 1

in the notification payload add sound key

{
    "to" : "bk3RNwTe3H0:CI2k_HHwgIpoDKCIZvvDMExUdFQ3P1...",

    "notification" : {
      "body" : "great match!",
      "title" : "Portugal vs. Denmark",
      "icon" : "myicon",
      "sound" : "default"
    }
  }

check this also Firebase push notification with custom sound (Flutter)