This does not appear to be an actual tournament and is actually a very realistic looking parody. The young man does indeed dominate in basketball against girls, but the videos he makes are staged to a degree. He is a YouTuber that makes basketball related content and does this sort of stunt to go viral. I'm not sure of his politics so I don't know if this particular stunt was for any reason other than to get views.

There are a number of moments in his two "Jayla" videos where his teammates and coach seem to be breaking character a bit, they appear to be in on the joke. The spot at the end of the "tournament" where they pose is a fixed spot in the facility and used for all sorts of random tournaments, and the trophy they are holding is from a tournament that occurred months ago in a totally different state from the facility where this was filmed.

I'm not sure if the girls in the video are friends of the YouTuber, paid actors, or something else, but they do seem to be having fun and actually playing. It is not uncommon for kids to practice against "ringers" like this to improve their skills. The game in the "tournament" video is probably a scrimmage of some sort.

TL;DR: Video is staged, this story did not actually happen.