Advertise the sponsor or something similar. Periodically display the logo or something like that. It just makes sense to do this when there are many viewers watching (online, I think at least 1000).

Okay, that makes sense, but it's still too early. It's not worth rushing in the next six months. We need to arrange a long-term partnership. It's not worth doing it haphazardly. Moreover, no one will agree to just one or two tournaments. We need to conclude a contract for a year with a well-thought-out approach to the games. And the sponsor should clearly know who will be doing what and when. First, we need to create a structure among ourselves and not get confused, and then present proposals and even give guarantees. Otherwise, it's like a kindergarten when people register and then not only don't play, but they're also nowhere to be seen during the entire tournament; the same can happen with streaming if, for example, someone has internet problems.
Yes, by the way, before approaching sponsors, we need to solve the problem of save files and cheating; there shouldn't be any of this negativity. And sponsors definitely don't want the reputation that the tournament they sponsored was won by a cheater and a bad boy. And rumors, as you know, can severely damage a reputation.