Can't show or schedule notification with flutter workmanager

I'm building an app with Flutter for Android and iOS that every day should check for new data and send a notification to the user. To achieve it, I'm using workmanager, to schedule the job, and flutter_local_notifications to show the notification.

When the job runs, no notification is shown and no exception get caught.

However, if I try to display a notification as per flutter_local_notifications docs, i.e. without workmanager, it works correctly.

This is a MRE of my main.dart that shows how I'm scheduling the job and showing the notification:

import 'dart:io'; import 'package:flutter_local_notifications/flutter_local_notifications.dart'; import 'package:intl/intl.dart'; import 'package:timezone/data/latest_all.dart' as tz; import 'package:timezone/timezone.dart' as tz; import 'package:workmanager/workmanager.dart'; import 'package:intl/date_symbol_data_local.dart'; final localNotificationPlugin = FlutterLocalNotificationsPlugin(); bool _initialized = false; void main() async { await initialize(); Workmanager().initialize(callbackDispatcher); runApp(App()); } @pragma('vm:entry-point') Future<void> initialize() async { WidgetsFlutterBinding.ensureInitialized(); await initializeDateFormatting(Platform.localeName, null); await initLocalNotificationPlugin(); tz.initializeTimeZones(); tz.setLocalLocation(tz.getLocation(DateTime.now().timeZoneName)); } Future initLocalNotificationPlugin() async { if (_initialized) { return; } _initialized = true; const AndroidInitializationSettings initializationSettingsAndroid = AndroidInitializationSettings('@mipmap/ic_launcher'); final DarwinInitializationSettings initializationSettingsDarwin = DarwinInitializationSettings(); final InitializationSettings initializationSettings = InitializationSettings( android: initializationSettingsAndroid, iOS: initializationSettingsDarwin ); await localNotificationPlugin.initialize(initializationSettings); } @pragma('vm:entry-point') void callbackDispatcher() { Workmanager().executeTask((task, inputData) async { print('callbackDispatcher'); try { await initialize(); } catch (e) { print("Exception on callbackDispatcher"); print(e); } switch (task) { case "fetchAndShow": await sendNotification(); break; default: // Handle unknown task types break; } return Future.value(true); }); } @pragma('vm:entry-point') Future<void> sendNotification() async { try { await localNotificationPlugin.show( 0, "Notification Title", "Notification Body", NotificationDetails( android: AndroidNotificationDetails("channel_id", "channel_name") ) ); } catch (e) { print('Exception on sendNotification'); print(e); } } class App extends StatelessWidget { @override Widget build(BuildContext context) { Workmanager().registerPeriodicTask('dataSync', 'fetchAndShow', frequency: Duration(days: 1)); // Build logic } }

I'm using:

flutter: ^3.9.2 intl: ^0.20.2 flutter_local_notifications: ^19.5.0 timezone: ^0.10.1 workmanager: ^0.9.0+3