GC doubt

so i've seen some dudes playing in women's league, a dude who was born as a MALE is now playing a womens tournament. so how does this work? Like does riot has some kind of medical checkup or do the dudes who are claiming to be a women should submit some kind of medical certification that proves that they are cis women or smthg?
whenever i see a controversy thread on gc i've wanted to give my opinion too but i don't really know how this gender transformation thing works. Can someone explain please.

There is this thing called ID, which usually tells if someone is a male or a female. No need for Leo faria to check people's pants

ever heard of books? education? shit like that....