So, I was speedrunning but didn't notice about the rules saying it needed to be offline which I assumed that it was singleplayer which wasn't that smart of me but I went with it. I decided to launch my server with only me being in it and typing into direct connect "localhost" as that's how I connect to my game. I recorded the footage and showed in the beginning of the speedrun that I was the owner. The video is not up yet but I'm wondering about if it's vaild to be one or not since I did do it solo but it was on my server with me being the only person in it.

Yes, this is fine. You need to setup your own server on localhost and show you are the only person connected to it!

I verified your run :)

Thank you very much!