Players need to have Google or Apple account to make purchases in Aquuua Casino and the account need to be connected with credit card or to redeem a gift card.
Once your account is set up with supported purchase option, purchase can be done. Please refer to below instruction for more detail steps.
How to set up payment for Google Play (AOS):
https://support.google.com/googleplay/answer/4646404?hl=en&ref_topic=3365267
How to set up payment for App Store (iOS):