Flutter Pushy 错误：未处理的异常：MissingPluginException在通道 me.pushy.sdk.flutter/methods 上找不到方法通知的实现

如何解决Flutter Pushy 错误：未处理的异常：MissingPluginException在通道 me.pushy.sdk.flutter/methods 上找不到方法通知的实现

我将 pushy-flutter 用于推送通知服务。但是我的应用程序无法在应用程序被杀死时推送通知。它仅在应用程序运行或我最小化应用程序时运行良好。从调试控制台，我可以看到应用程序已成功收到通知

[+8340 ms] D/Pushy   ( 6919): Received push for package com.afabasia.afab
[        ] D/Pushy   ( 6919): {message=Hello Hell}
[   +8 ms] D/Pushy   ( 6919): Invoking push receiver via reflection: 
me.pushy.sdk.Flutter.internal.PushyInternalReceiver
[        ] D/Pushy   ( 6919): Handling notification in Flutter background isolate
[   +4 ms] I/Flutter ( 6919): Pushy: _isolate() received notfication
[   +2 ms] I/Flutter ( 6919): Pushy notification received: {__json: {"message":"Hello Hell"},message: Hello Hell}
[        ] I/Flutter ( 6919): Received notification: {__json: {"message":"Hello Hell"},message: Hello Hell}

但是当我调用函数 Pushy.notifiy(...); 时，它显示了这个错误

[  +14 ms] E/Flutter ( 6919): [ERROR:Flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: MissingPluginException(No implementation found for method notify on channel
me.pushy.sdk.Flutter/methods)

我已经尝试过 pushy 演示项目，它一切正常，只有在我的项目中，当应用程序被终止时，它无法推送通知。我是否错过了一些配置，以至于我的应用在应用被杀死后无法获取 Pushy 库？

以下是我的Flutter doctor -v

[√] Flutter (Channel stable,1.22.1,on Microsoft Windows [Version 10.0.18363.1440],locale en-MY)
    • Flutter version 1.22.1 at C:\Users\zhanm\Desktop\Flutter sdk\Flutter_1.22.1\Flutter
    • Framework revision f30b7f4db9 (6 months ago),2020-10-08 10:06:30 -0700
    • Engine revision 75bef9f6c8
    • Dart version 2.10.1

[√] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
    • Android SDK at C:\Users\zhanm\AppData\Local\Android\Sdk
    • Platform android-30,build-tools 30.0.2
    • ANDROID_HOME = C:\Users\zhanm\AppData\Local\Android\Sdk
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b04)
    • All Android licenses accepted.

[√] Android Studio (version 3.6)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin version 49.0.1
    • Dart plugin version 192.8052
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b04)

[√] VS Code (version 1.54.3)
    • VS Code at C:\Users\zhanm\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.20.0

[√] Connected device (1 available)`
    • Android SDK built for x86 (mobile) • emulator-5554 • android-x86 • Android 10 (API 29) (emulator)

• No issues found!