Sorry but I am going to have to call BS on this. I do not think that any sportsbook could handle a $45 million dollar bet nor am I sure whether they would accept such a bet, due to the reason (I suspect) that they do not have enough money to pay the gambler off, should he win.
Casinos are all about people betting normal amounts many, many times. Because thats how they win with probability (since they have the house edge). But they themselves are not risk-takers. And a 45 Mill bet is too high a risk to take without insurance.
You clearly misunderstood what he stated just like so many others in this thread which is pretty embarassing. He stated that he wagered millions, but he never mentioned that he wagered it all on a single bet.
I'm not a huge fan of any of the crypto sites. If you're in the US its best to stick with the regulated companies.
Fanduels, Draftkings, Unibet, Betrivers etc? They limit pretty quickly which is why some crypto books are a great alternative.