It’s hard to offer any advice without knowing what game you requested. But generally speaking, you need to provide information about the run (through some notes about it or in a description of the video) that shows that you aren’t just casually playing through the game. In other words, there needs to be some evidence of you putting some thought into running the game and it’s route. Sometimes this is evident through the video, other times it might need some explaining. You also have to show a full run of the game, not a simple IL or something.

Additionally, you need to provide info about the game, usually a link to a page like Wikipedia or Steam that shows it’s not a dike a dozen game and is actually a real, full game with some kind of substance to it.

On the note of evidence that you aren't just playing casually, for the one game I've personally submitted, I included a link to the fandom wiki, which features a page on how to speedrun the game. Plus, the video I included showed that page a few times because I hadn't made a physical copy of the route notes and needed to check a few things.