want to add custom sound in flutter

Question

i successfully add an sound into copy bundle.but the notification sound does not work in ios

Future simpleNotificationShow() async { AndroidNotificationDetails androidNotificationDetails = const AndroidNotificationDetails('noti', 'noti notification', priority: Priority.high, importance: Importance.max, playSound: true, icon: '@mipmap/ic_launcher', channelShowBadge: true, sound: RawResourceAndroidNotificationSound('notification'), );

NotificationDetails notificationDetails =
NotificationDetails(android: androidNotificationDetails, iOS: DarwinNotificationDetails(
  presentAlert: true,
  presentBadge: true,
  presentSound: true,
  sound: 'notification_.aiff',
));
await _notiPlugin.show(
    0, 'Simple Notification', 'New User send message', notificationDetails);

}

this is example of my code.