Ionic DevApp: Google maps not showing

Appflow
1

I have used JavaScript SDK to display map.

It’s working on the browser but when I open it on dev app, the page shows blank page.

 ionViewDidLoad(){
    this.loadMap();
  }
 
  loadMap(){
 
    this.geolocation.getCurrentPosition().then((position) => {
 
      let latLng = new google.maps.LatLng(position.coords.latitude, position.coords.longitude);
 
      let mapOptions = {
        center: latLng,
        zoom: 15,
        mapTypeId: google.maps.MapTypeId.ROADMAP
      }
 
      this.map = new google.maps.Map(this.mapElement.nativeElement, mapOptions);
 
    }, (err) => {
      console.log(err);
    });
 
  }
2

same issue and with google plus

3

Same issue, any solutions so far ?