About LocalNotifications in Ionic-Native

Hi, I have a basic question, when i try to use the local notification from ionic native, i couldn’t retrieve the promise from the LocalNotification.schedule() function.
Is this a wrapper function to the existing cordova plugin or is it different. Since from the ngCordova documentation which i used on ionic1, i see a promise / a return function from functions like schedule, but when i was checking for a promise in my current project TS file, it just reported "“Error TS2339: Property ‘then’ does not exist on type ‘void’.”"
When i remove the then function my notifications are getting triggered. But not sure what’s happening here.

This is what i was trying to do (TS):

            at: alarmTime,
            text:"Time to checkout",
            title:"Hello there!!!",
        }).then((result) => {
            console.log("result from notification:",result);

Similar to this existing wrapper from ngCordova:
        id: 1,
        title: 'Title here',
        text: 'Text here',
        at: _10SecondsFromNow
      }).then(function (result) {
        // ...


Ionic-native’s Local Notification wrapper for schedule actually is not a promise.

You just create the notification and that’s it. So no .then after it.