Where is the zip or postal code box in the credit card payment form?
If you're trying to pay with a credit card and do not see a zip code or postal code entry field, don't worry! That field appears automatically at the far right of the credit card entry field once you start typing in your credit card number, as shown in the screenshot below.
If it does not appear for you, please try another browser--sometimes ad blockers or extensions can interfere with the code in the credit card field that makes this work.
If that still does not work for you, please try another credit card or PayPal, if that's an option for you.