How to put overlays in the background behind the graph itself in bpmn-js?

Hello, I want to make a map on which it will be possible to place bpmn markers, linking to a certain area. I found two implementation options: 1) Put the map in overlays, in this case it is not clear how to put overlays on the background, behind the graph 2) Make the map a bpmn element, in this case it is not clear how to fix it and make it inactive.

Who can help me? strong text

We don’t support this. Italic text

But if you provide some more details on what you’d like to accomplish and why we may be able to help.