Thanks for digging around for me. I added the port to my conf and tried adding my token to plex.conf like that other thread suggested. Still no luck.
I think it’s definitely something to do with authentication.
I’m running both Plex and Home Assistant as docker containers on UNRAID. When I add my desktop (different PC) IP address to the PMS network setting for “doesn’t require auth” then I can use curl to access the API. But if I remove that IP address and try to access the API with my username and password it doesn’t work. Maybe I’m doing something wrong there.
For some reason adding the IP address of my UNRAID server to that section of PMS settings doesn’t seem to work. I SSH into my server and can’t use curl like I can on my desktop. Maybe something to do with docker?
Some progress: I can now use curl to access the API from any machine on my LAN (even if not on the PMS list) by adding my token to the url being passed to curl.
Also, I noticed that if I leave my username/password out of my config then I get an error showing unauthorized from the IP of the PMS, but if I put it in then I get the error above showing plex.tv/443.