i don't see any submit level button, how do i do it?

You go to the level leaderboard, click on submit your level run here, submit your run there with all the info, and then it will be moved. https://prnt.sc/t3ilwq

Well thanks a lot @aggelbeatboxer

also another question: why do levels made for the run get rejected?

@FalcoDash107 there are a few reasons why it is a rule, but generally to prevent people from making a "backdoor" in the level to ease the level complition. Example: trigger in the random spot of the map.