We apologize for the inconvenience, but we have contacted Prepaid Digital Solutions (our provider for the Visa cards) about this issue and they are working to add Ukraine to their country list.
In the meantime, you can redeem your gift card by changing a couple of steps during the gift card process on https://www.prepaiddigitalsolutions.com/. Enter your country code when prompted and then choosing a different country on the list. Once you have entered your address (without the country), press continue and then change the “My Currency” option to UAH. Your billing address will be wrong, but you will be able to update the shipping address as you purchase.