Every casino, as a rule, has a dedicated page with bonus codes listed. Open that page & copy a code that’s needed. Sometimes, gambling facilities offer automated granting of the code after registration is completed. But that’s good only for new players. Existing ones should use codes copied from that page. Also, promo codes are found online as a part of the promotional strategy of this or that gambling house. They can be more lucrative than codes listed inside the casino, so don’t hesitate to browse the Internet once in a while.