What happens when you click on it? It's red because you haven't set the URL.
Just to be clear, there are no different versions of Traccar. Self hosted is exactly the same thing as we have on our servers.
Actually it needs to be set in the server settings.
Are custom overlays not available on self hosted servers? Mine is in red and won't let do anything with it.
I looked at the custom Overlay help page but maybe I don't understand it.