颤振本地通知在真实设备(Android)上不起作用

我正在使用flatter构建一个Android应用程序。我的应用程序需要显示本地通知。我在用这个软件包, https://pub.dev/packages/flutter_local_notifications .当我在模拟器上显示通知时,它正在工作。但当我编译release APK并将其安装到实际设备上时,它不起作用。

这是NotificationService类

import 'package:flutter_local_notifications/flutter_local_notifications.dart';

class NotificationService
{
  static FlutterLocalNotificationsPlugin? flip;

  static FlutterLocalNotificationsPlugin getFlipInstance()
  {
    if (flip == null) {
      flip = FlutterLocalNotificationsPlugin();

      // app_icon needs to be a added as a drawable
      // resource to the Android head project.
      var android = const AndroidInitializationSettings('@mipmap/ic_launcher');
      var ios = const IOSInitializationSettings();

      var settings = InitializationSettings(android: android, iOS: ios);
      flip!.initialize(settings);
    }

    return flip as FlutterLocalNotificationsPlugin;
  }


  static Future showNotification(String title, String body) async {
    var androidPlatformChannelSpecifics = const AndroidNotificationDetails("your channel id", "my channel name");
    var iOSPlatformChannelSpecifics = const IOSNotificationDetails();

    // initialise channel platform for both Android and iOS device.
    var platformChannelSpecifics = NotificationDetails(android: androidPlatformChannelSpecifics, iOS: iOSPlatformChannelSpecifics);

    await getFlipInstance().show(0, title,
        body,
        platformChannelSpecifics, payload: 'Default_Sound'
    );
  }
}

我在主页的initState方法中显示这样的通知。

@override
  void initState() {
    super.initState();
    setState(() {
    NotificationService.showNotification("Local Notification", "Local Notification Message");
  }

正如我提到的,它在模拟器上工作。但是,当我生成一个APK并将其安装到真正的设备上时,它不起作用。