Can’t use apple card

so, I redeemed my Apple Gift Card on the apple.com/redeem site and it worked. Then, when ever I tried to buy something, it was acting like no payment options were there! An error message would pop up and say, “no money on account” or something like that. It would send me to a credit card option (don’t have one yet) and so I would click back, see my Apple Card, click it, and no options to use it would come up and I’ve tried looking through YouTube and searching it and looking for answers on this site, but I’ve still seen no answers to my problem. If you can help me, thanks.