SystemNavigator.pop() not being called in notificationTapBackground()

Question

I am using flutter_local_notifications to create notifications with actions.

final _notificationDetailsWithActions = NotificationDetails(
   android: AndroidNotificationDetails(
   notificationChannel.id,
   notificationChannel.name,
   channelDescription: notificationChannel.description,
   importance: notificationChannel.importance,
   priority: Priority.high,
   actions: <AndroidNotificationAction>[
   const AndroidNotificationAction('id_exit', 'Exit',
      cancelNotification: true),
  ],
 ),
  iOS: const DarwinNotificationDetails(
  presentAlert: true,
  presentSound: true,
  presentBadge: true,
  sound: 'notification.wav',
 ),
);

then I have

await _flutterLocalNotifications.initialize(
  settings,
  onDidReceiveNotificationResponse:
      (NotificationResponse notificationResponse) {
  },
  onDidReceiveBackgroundNotificationResponse: notificationTapBackground,
);

and

@pragma('vm:entry-point')
void notificationTapBackground(NotificationResponse notificationResponse) {
  // ignore: avoid_print
  debugPrint(
  'notification(${notificationResponse.id}) action tapped, actionId: 
  ${notificationResponse.actionId}');
  if (notificationResponse.actionId == exitActionId) {
    debugPrint('close app');
    SystemNavigator.pop();
  }
}

For some reason SystemNavigator.pop(); is never called. Basically I want to close the app as well as a background service that I have running.