onBackgroundMessage method
Implementation
@override
void onBackgroundMessage(Function onRecieve) {
// FirebaseMessaging.onBackgroundMessage((RemoteMessage message) {
// if (message.notification != null) {
// debugPrint('OnBackground notification title: ${message.notification!.title}');
// debugPrint('OnBackground notification body: ${message.notification!.body}');
// }
// });
}