Registered for Plex Cloud, can't find my local server
I'm a new user of Plex on a FreeNAS Mini XL. I purchased the lifetime license and was presented with a screen that offered to first configure Plex Cloud, then Plex (something else, possibly server). I configured Plex Cloud to use my Google Drive and added my Google Photos folder. It shows empty boxes for the photos (instead of a thumbnail image), but I can use the download link in the bottom right corner menu and it will download the photo as expected.
Unfortunately, I haven't found a way to add my local Plex server, even though the URL I'm using (http://plex.markwaite.net:32400/web/index.html) is the URL of my local server.
I installed Plex server using the FreeNAS PlexMediaServer plugin. I created a /plex-media/ folder and assigned ownership nobody:nogroup to it and all its subdirectories. I've confirmed that I can copy media to those subdirectories, including /plex-media/Media/Movies and /plex-media/Media/Photos.
Unfortunately, I can't see any way to add the locations in the /plex-media/ directories so that they will appear in the Movies or Photos.
When I look at the "Servers" page, it only shows "Plex Cloud".
Can you guide me to documentation or other information that will help me correct whatever mistake I made that has made my local Plex server unable to find media on that server?