You don't need to send a personal information to them maybe you can send only the proof that you deposited to that casino. You need to hide all your personal information as this day's many are getting scam because they send personal information. Please be careful about what you are doing.
The one who's has the biggest power is the casino, not the gambler.
If the casino ask you to give your bank statement, but you said you can't and only able to send proof of deposit, they will not listen your opinion because their decision are final. If you can't send it, then the casino don't have any problem, they can confiscate your funds and they're profit from it.
It's not that simple. A casino should find a common ground with the client. It's not like they can demand a single thing and if that's not provided take your funds.
For instance, if they demand a proof of residence in the form of utility bill and you cannot give them that because you don't pay the bills in that building, it doesn't give them the right to take your money.
It's possible that a client of a crypto casino doesn't have a bank account.