Pretty much any modern online or crypto casino asks for KYC verification at any time they deem necessary. Don't tell me you did know this because if you take any effort to skim through their terms of service. Privacy policy or AML policy. You will see a mention of KYC verification.

Now that your case has been resolved, and it didn't turn out a scam as your title and OP suggested, I think it is more than fair if you add "Resolved" to the title for future reference by other users who might come across this thread.