Select KML boundary files from lat/long in angular 5

I am facing an issue in selecting kml boundary from lat/long here is my code :

setCenter(e:any){
e.preventDefault();

this.map.setCenter(new google.maps.LatLng(this.latitude, this.longitude));

this.mapsAPILoader.load().then(() => {
  var latlng = new google.maps.LatLng(this.latitude , this.longitude);
  var marker = new google.maps.Marker({
  position: latlng,
  map: this.map
  });

  this.kmlLayer_1 = new google.maps.KmlLayer({ url: "https://url.kml"});
  this.kmlLayer_1.setMap(this.map);

});

}