Angular to VueJS converting example code

With the Ionic Native there is the possibility to use iBeacons via a native-plugin: https://ionicframework.com/docs/native/ibeacon

The example code is written for people that use Ionic with AngularJS, but I’m using VueJS and I cannot figure out how to get this to work:

The Angular version of the Example code:

import { IBeacon } from '@ionic-native/ibeacon/ngx';

constructor(private ibeacon: IBeacon) { }

...


// Request permission to use location on iOS
this.ibeacon.requestAlwaysAuthorization();
// create a new delegate and register it with the native layer
let delegate = this.ibeacon.Delegate();

// Subscribe to some of the delegate's event handlers
delegate.didRangeBeaconsInRegion()
  .subscribe(
    data => console.log('didRangeBeaconsInRegion: ', data),
    error => console.error()
  );
delegate.didStartMonitoringForRegion()
  .subscribe(
    data => console.log('didStartMonitoringForRegion: ', data),
    error => console.error()
  );
delegate.didEnterRegion()
  .subscribe(
    data => {
      console.log('didEnterRegion: ', data);
    }
  );

let beaconRegion = this.ibeacon.BeaconRegion('deskBeacon','F7826DA6-ASDF-ASDF-8024-BC5B71E0893E');

this.ibeacon.startMonitoringForRegion(beaconRegion)
  .then(
    () => console.log('Native layer received the request to monitoring'),
    error => console.error('Native layer failed to begin monitoring: ', error)
  );

But… what I expected to work was the following in VueJS:

On top of my component importing it: import { IBeacon } from '@ionic-native/ibeacon/ngx';

And use it like this:

foobar() {
let _ibeacon = IBeacon.Delegate()
  alert('Hi iBeacon');
  _ibeacon.didStartMonitoringForRegion()
    .subscribe(
      data => console.log('didStartMonitoringForRegion: ', data),
      error => console.error()
    );
}

But even the alert isn’t shown.
What IS the correct way to use the iBeacon plugin with Vue and ionic?