If a credit card is your only option, you can use it to get a from an ATM or bank branch and then use that cash to buy the money order. Important Warnings: Sending Money Orders - USPS
Cash, debit card, or traveler’s checks only. Walmart: Cash or debit card only. where can you buy money order with credit card
The following major providers accept direct credit card payments for money orders: If a credit card is your only option,