iCloud

You won’t have to do anything other than upgrade the iCloud storage on your device. As long as you have a balance in your Apple ID account, you can pay for everything using iTunes gift cards. Just make sure that you always have money in your account by redeeming iTunes gift cards.

We use Family Sharing and I am the organizer. We have Shared Family iCloud storage that I pay for every month using iTunes gift cards. In fact, each family member pays for their own purchases by using iTunes gift cards that they redeem to their own Apple ID’s and we never have to use my debit card at all.

Buy more iCloud storage - Apple Support

Yes. As long as you maintain a balance in your Apple ID account by using iTunes gift cards, you will never have to use your debit card. All of your purchases will be drawn from the funds that you redeem with gift cards. If you want to continue to pay the monthly subscription without using your debit card, just make sure you always have enough money in your account from the gift cards.

I haven’t had to use my debit card in two years because we all us iTunes gift cards for purchases.

Yes you can. You will need to add the gift card as a balance to your Apple ID in order to do so. To do that, open the app store, go to your account and select 'Redeem Gift Card or Code'.

You’re welcome.