I’m just curious because in the rules it says no emulators, but when you submit a run, there’s a checkbox that says “emulator”. Can someone clarify this for me? And if it’s not allowed, why?

I would assume no, but I'm probably not qualified to answer that lol

its markd as EMU

I mean like bob or wf speedruns

It's allowed for single stars, but not for stage RTA. Technically both of those fall under IL's (depending on whether or not you quantify stars or stages as 'levels'). Assuming you are referring to the submissions on this website, (single star records are not stored here on speedrun.com) which are the stage RTA boards, then no you can't use emulators.