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.
This happens, because we go through their terms and conditions and agree for it while signing up. As said the casinos say the gamblers were the king, but the reality is against it. The casinos were the kings, because they've got control over the funds and for withdrawal and other needs we need to provide supported documents if requested. This is commonly found almost with every gambling platform when there arises a doubt on the fund deposited.