Ionic 3 onesignal go to specific page

Ionic Framework ionic-v3
1

Hi,

I have an ionic 3 with onesignal And I want to go to specific page.

Please see my app.component

  var notificationOpenedCallback = function(jsonData) {
        if (jsonData.notification.payload.additionalData != null) {
          this.nav.setRoot(TicketsPage);
        } else {
          console.log("no addtional data");
        }
     
      }


      window["plugins"].OneSignal
        .startInit(this.singal_app_id, this.firebase_id)
        .inFocusDisplaying(OneSignal.OSInFocusDisplayOption.InAppAlert)
        .handleNotificationOpened(notificationOpenedCallback)
        // .sendTags({
        //   latitude: 14.5571963,
        //   long: 121.00696984
        // })
        .endInit();
      window["plugins"].OneSignal.setSubscription(true);
      window["plugins"].OneSignal.promptLocation();

it says nav is null