Licensed online casinos have to follow the regulations of gambling authorities. One of such regulations is compliance with the KYC policy. It stands for Know Your Customer, which means that before any financial operation, the casino must know your personal information. But don’t worry, you only need to do it once while making your first withdrawal request.
https://casinobest.ca/faq/why-do-i-have-to-verify-my-casino-account-to-make-a-withdrawal/