View Google Maps on Xamarin Android

I try to call Google Maps from Xamarin's Api, but when I run my application it goes blank without showing me the map (only the Google logo below) So I call my map:

 public void OnMapReady(GoogleMap map)
    {
        GMap = map;
        //this.GMap = googleMap;

        LatLng latlng = new LatLng(40.776408, -73.970755); //New York
        LatLng latlong = GetCurrentLocation();

        CameraUpdate camera = CameraUpdateFactory.NewLatLngZoom(latlong, 10);
        GMap.MoveCamera(camera);

        MarkerOptions options = new MarkerOptions()
        .SetPosition(GetCurrentLocation())
        .SetTitle("New York")
        .SetSnippet("AKA: The Big Apple")
        .Draggable(true);

        GMap.AddMarker(options);

        //GMap.MarkerClick += MMap_MarkerClick;
        //GMap.MarkerDragEnd += MMap_MarkerDragEnd;
    }

Any idea what could fail me? I use an Api Key generated from the official site

UPDATEEST

I already generated the SHA-1 but now it does not execute the application, it opens it but it closes