Plex question with wireguard

I have set up wireguard and have a working plex server. I tested it with my android phone connecting to it with the android client app coming in from the internet and all seems to be working ok. The android app scanned and found the server and displayed some test movies I put there with out any issue.

I registered with plex because it said something to the effect that it would make my friends and family find the server with out much trouble with their client. What they did not really explain is do they use my login or can they set up their on login and still find my server.