If you work in a company that pays you with Bitcoin or other crypto. the company will still give you a monthly pay slip like a company that gives a fiat salary. you can use that, but if you mean transactions that occur in your wallet, I'm sure it won't be enough for the casino.

Usually what the casino asks for for a source of income report is proof of bank account and pay slip. that will help you get through your problems. but if you only think about transactions in your wallet, I'm sure the casino will not be satisfied or even reject it.