The container expects its mounted folders to exist already, before it's created. Either create the following or mount a drive to /data/plex that has your data.

/pwspool/plex/tvseries
/pwspool/plex/movies
/pwspool/plex/photos
/pwspool/plex/homevideos
/pwspool/plex/transcode

(If Docker has been installed with snap, while installing the OS, you'll have issues here. It's better to seperately install docker-ce and docker-compose.

Start with Docker Compose:

docker-compose up -d

Start with Plain Docker

docker run -d --name=plex --net=host -e PUID=1000 -e PGID=1000 -e VERSION=docker -e PLEX_CLAIM= #optional -v /data/persistent/plex/library:/config -v /data/persistent/plex/tvseries:/tv -v /data/persistent/plex/movies:/movies -v /data/persistent/plex/transcode:/transcode --restart always ghcr.io/linuxserver/plex

Notes

When navigating to plex, assuming no nginx routing is happening, you must go to http://[ip address]:32400/web/index.html#!/ for first time setup. Just going to port 32400 doesn't work for some reason until after the setup is complete.