My apologies, i meant add a resource towards this one which i made a screenshot for ya.. click that and add the resources .btn/.pas files and then delete that other resource after that you upload so then both resources are combined. The way you did it is fine with the asset but that is more when someone wants to add a skin/model towards there icon that goes with it.
*Also, youll find "Add Resource" right by your icons /BTN /PAS buttons on the right side.
Hope this makes sense, let me know if it doesn't. <3