Уведомление Unity OneSignal не отображается

Я пытаюсь внедрить OneSignal PushNotifications в свое приложение Unity, но никогда не получаю уведомление. Пожалуйста помоги! Кроме того, HandleNotificationReceived никогда не срабатывает!

Вот как я инициализирую OneSignal:

void Start()
    {
        extraMessage = null;

        OneSignal.SetLogLevel(OneSignal.LOG_LEVEL.VERBOSE, OneSignal.LOG_LEVEL.NONE);

        OneSignal.StartInit("633492bf-e776-464c-ad6a-d06bc3b62e9f")
               .HandleNotificationReceived(HandleNotificationReceived)
               .HandleNotificationOpened(HandleNotificationOpened)
               .EndInit();

        OneSignal.inFocusDisplayType = OneSignal.OSInFocusDisplayOption.Notification;

        OneSignal.permissionObserver += OneSignal_permissionObserver;
        OneSignal.subscriptionObserver += OneSignal_subscriptionObserver;
        OneSignal.SendTag("data", "data");

        var pushState = OneSignal.GetPermissionSubscriptionState();
        Debug.Log("pushState.subscriptionStatus.subscribed : " + pushState.subscriptionStatus.subscribed);
        Debug.Log("pushState.subscriptionStatus.userId : " + pushState.subscriptionStatus.userId);
        GameDefaults.PUSHID = pushState.subscriptionStatus.userId;

        OneSignal.ClearOneSignalNotifications();

    }

А это функция-обработчик:

private static void HandleNotificationReceived(OSNotification notification)
    {

        OSNotificationPayload payload = notification.payload;
        string message = payload.body;
        ToastMessage.Instance.showToastOnUiThread("Message: "+ message);

        print("GameControllerExample:HandleNotificationReceived: " + message);
        print("displayType: " + notification.displayType);
        extraMessage = "Notification received with text: " + message;

        Dictionary<string, object> additionalData = payload.additionalData;
        if (additionalData == null)
            Debug.Log("[HandleNotificationReceived] Additional Data == null");
        else
            Debug.Log("[HandleNotificationReceived] message " + message + ", additionalData: " + Json.Serialize(additionalData) as string);
    }