My credit card is set up through Apple Pay and it was automatically linked to my app subscriptions. But recently, my card has not been working.

My credit card is set up on my phone for Apple Pay. And it was also set up for my app subscriptions. But recently, it stoped working for the subscriptions. When I attempt to purchase something through an app, and double click the side button, I get a notification about adding a payment. So over and over I have RESUBMITTED my cc info, and then get a notification that no valid card was found in my wallet for iTunes. I am so Confused... I’ve read all the articles ...

made many attempts... I don’t know what else to do.