Gift card for in app purchases

So I got an iTunes gift card and it has been working well for buying apps. However, when I started to buy in app purchases, everything started to go downhill. It would start to ask for verification of a payment method which seemed normal but it didn’t allow me to select the gift card as shown in the picture below. I am on a family account which links me to the family shared card but I should be able to select the gift card. I’m sure there is an easy fix but I couldn’t find one.