Why is a Russian customer's MasterCard payment being declined at checkout?

I have a customer in Russia who’s trying to checkout with a bank card ( that is master card affiliated ) from Kazakhstan trying to checkout a order on my store but it’s being declined, is this because of the ban on Russian customers with the ongoing conflict or another issue? Since they can’t use PayPal to checkout due to the ban or Etsy I’m trying to figure out a way to let them complete their order.
thanks

Hi, @Starsailorlew

Any sanctions, restrictions and/or suspensions for Russian cardholders will be set by their banking institution or credit card provider. They are responsible for any failed attempts at payments.

Depending on how restricted the customer is at the moment, it would be possible for you to offer a manual payment method such as Cash on Delivery, Bank Deposit or Money Order.

I hope this helps.

Best,