I’m not able to add or edit any payment methods

At the moment on my iphone I only have a shared apple card, and I’m not the organizer. I’m unable to make any purchases, or add any new payment methods as the “edit” button is greyed out. I’m unable to change anything. Any way to get the edit feature available again?? I have other cards stored in my apple wallet (and a paypal) but I can’t add them to my payment options for the app store.