There's this Kodi addon: PlexKodiConnect: let Kodi talk to your Plex — Plex ForumsThere's also a LibreELEC fork with Plex Media Player in the works, not sure about how far it's come: GitHub - plexinc/LibreELEC.tv: 'Just enough OS' for Kodi
It's been released as "Plex Embedded" for pi and x86_64 hardware .. available to Plex Pass holders according to the developer folks who work on it. There is also "RasPlex" which continues development of the older PHT client; also rebased/converted to LE.