You did not complete the form when trying to add a new payment method, even tho the payment form is completely filled

I went to my App Store and it was already set up with a different payment method but I didn’t have any money on my other card. So I clicked on add a new payment method, and put in my information then pressed submit. When I clicked submit, red lettering popped up saying “you did not complete the entire form” in which I have filled out the entire payment information along with my address, name etc. please help