Gaming and gambling payments can have additional requirements, so your payment may be declined due to local gambling rules. 

For example, the funding method you used when depositing may not be allowed for gambling payments.

If an error “Payment declined. Payments to this site are not allowed.” pops up, the payment may be blocked because of the merchant’s internal policies, local regulations, or the payment method selected. Contact the merchant to confirm what they can accept, try another available funding option, or choose another supported way to use your funds. 

In case of a verification prompt, go to Settings/Profile > Verification & features in your wallet account, complete the requested steps, and try again once the review is finished. 

If you deposited money with a non-gaming purpose of use and are trying to pay a gaming or gambling merchant, you may need to make a new deposit with gaming as the purpose of use, where available.

 
In some countries, credit cards are not allowed for gambling payments. If this applies, try another available funding option or contact the merchant to confirm the sort of payments they accept.