node-kodi-ws JSON-RPC get paths

I’m working on a NodeJS based backend, I’m communicating with kodi using ‘node-kodi-ws’.
This Kodi instance will run on a small server.

My own webpage should then be able to receive the current movies (and display their cover).
And when clicked on it, it should try to access the file (from either the server itself or via Kodi).

Getting a list of the movies is actually very easy, but how can I find (a path to) the cover-image and video file?