David Daud: I believe we do not have directly feature in existing google map widget to create Heatmaps. Do you want to change the marker to appear in some specific polygon image if so then can create a media type entity using the polygon shape which could be used in MarkerStyle.
You can implement polygons using the region functionality which is included in the out of the box google maps widget. You just need to create an infotable that contains a param of type "location". Each lat,long location point that you define in your infotable becomes a point in your polygon. You bind this infotable to the "RegionLocation" parameter in the google maps widget.