Parse markers loaded from a Json file

I have a set of features ( Markers and LineString) loaded from a GeoJson file.
I need to change the ImageAsset property to all markers loaded.
How to access its?

That's i how I load the Json:


Welcome Eolo.

Load your geojson file as a Feature Collection. If the file is too large, it probably will not render.

Perhaps one of these articles might be useful

If still stuck, provide a link to the geogson file(s) you are attempting to use.