I think there is some confusion. Gotta agree with Roland. It's better to have a non custodial (private key) wallet to do your business. In that sense what you do is buy the btc or any other crypto that you want to use for deposits/WD at your exchange (I personally love the fact that you can use ripple with
Betonline which is faster than BTC and Litecoin/exchanges I use are uphold and crytpo. Com although have a binance account )
So once you buy there you just send it to your wallet and operate from there back and forth from any sportsbooks.
Now, in that sense Rudy does have a valid point as to how originally buy btc if you don't have any to begin with, although I'm curious to see if you could make a deposit at an SB using dollars and make the WD in crypto because that's a game changer (depending on the btc price that book has) but might still be worth it to keep privacy to a maximum