How to configure Workmanager Flutter iOS correctly?

I create a background fecth with workmanager flutter and following as the instruction on their documentation [here]https://github.com/fluttercommunity/flutter_workmanager/blob/main/IOS_SETUP.md. On android is working properly, but I am not sure with ios.

I add this on my main.dart

void callbackDispatcher() {
  Workmanager().executeTask((task, inputData) {
    switch (task) {
      case Workmanager.iOSBackgroundTask:
        stderr.writeln("The iOS background fetch was triggered");
        break;
    }
    bool success = true;
    return Future.value(success);
  });
}

and call it on here

void main() async {
  .....
  //workmanager
  if (Platform.isIOS) {
    Workmanager().initialize(
        callbackDispatcher, // The top level function, aka callbackDispatcher
        isInDebugMode:
            true // If enabled it will post a notification whenever the task is running. Handy for debugging tasks
        );
  }
}

and I tested via simulator and simulate background fecth. And its print The iOS background fetch was triggered SwiftWorkmanagerPlugin - ThumbnailGenerator createThumbnail(with:) something went wrong creating a thumbnail for local debug notification

but the notification didn't appear as on the documentation did. Is my workmanager working?

Logically, I think is work, but im not sure. Also, it will running on background (even the apps is close/kill/terminated) every 15 minutes in iOS?