Purchase sharing on gift card.

I want to make an in app purchase in a certain app. My dad has purchase sharing on for me to get into Apple Music. The problem is, I want to use the gift card thinking it will avoid the family sharing option. I was wrong after some research and articles from Apple, support wasn’t really much help either. It also says to verify my dad’s credit card on payment options. The point is, I want to make a purchase on my gift card/ account balance and not my dad’s credit card. I have already redeemed the card, so is there a way to use the gift card? I don’t want to waste any money.