Mostly no! If you deposit and withdraw with Bitcoin, the Bitcoin Betting company does not have any risk of a chargeback or anything so they do not ask for any documents. If the crypto betting site that you are using offers deposits and withdrawals of fiat currencies with Credit Cards or any other traditional payment methods, they might want to verify your identity with documentation. So stick to cryptos and you will be fine without any documentation. The only other way they might ask for documentation is there might be some other people registering and taking their bonuses at your IP address and household. In that case you might have to prove that you are not a bonus abuser and you are the only one the house using their website.