如何在flutter中实现本地通知？

dependencies:
  flutter_local_notifications: ^5.0.0

import 'package:flutter_local_notifications/flutter_local_notifications.dart';

FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
    FlutterLocalNotificationsPlugin();

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await initializeNotifications();
  runApp(MyApp());
}

Future<void> initializeNotifications() async {
  const AndroidInitializationSettings initializationSettingsAndroid =
      AndroidInitializationSettings('app_icon');
  final InitializationSettings initializationSettings =
      InitializationSettings(android: initializationSettingsAndroid);
  await flutterLocalNotificationsPlugin.initialize(initializationSettings);
}

Future<void> showNotification() async {
  const AndroidNotificationDetails androidPlatformChannelSpecifics =
      AndroidNotificationDetails(
    'channel_id',
    'channel_name',
    'channel_description',
    importance: Importance.max,
    priority: Priority.high,
  );
  const NotificationDetails platformChannelSpecifics =
      NotificationDetails(android: androidPlatformChannelSpecifics);
  await flutterLocalNotificationsPlugin.show(
    0,
    'Notification Title',
    'Notification Body',
    platformChannelSpecifics,
  );
}

FlatButton(
  onPressed: () {
    showNotification();
  },
  child: Text('Send Notification'),
),