Add a new Plex server to your list (TrueNas)
TL;DR: User the server's IP address, not its (local) name.
Once the sever is configured, it's time to add it
plex
Setup Plex on FreeNAS (TrueNas)
Note: This entry assumes you got Plex up and running, but with an empty library. If you already set up the library, then good for