Paying with voucher

Hi, I bought my prepaid Sim Card a few days ago but I‘m unable to pay for a plan. I do have an international credit card, but I cannot register it because Koodo is asking for an american phone number to schedule the callback (I obviously don‘t have one yet). So I decided to try my luck with a voucher. Koodo is still asking for a credit card number even tho I‘m paying with a voucher. How do I pay for my plan? It’s frustrating to not have international credit cards or PayPal as an option.