I’m using this Docker image: https://hub.docker.com/r/linuxserver/plex. The logs suggest claiming via environment variable is working. Logging in allows me to see the settings for my other server but this remote one isn’t listed. Trying to go straight to http://ip:32400/web/index.html#!/setup/[41-char identifier] says I’m not authorised. It sounds like I need to open the server url from the device itself. I’ve attempted to use terminal browsers, i.e. w3m and Lynx, but they don’t display the page.
I had further issues related to DNS and another container for Pi-hole, etc, and ended up with the Plex container in bridge networking to eventually be able to claim it.