Apple won't let you download anything more until you have paid what you owe. Read the links below about various ways to pay for items in the iTunes and App Stores.
- Add a payment method to your account. See this article about payment methods that you can use with your Apple Account --> Payment methods that you can use with your Apple Account - Apple Support then see this article about how to add a payment method to your Apple Account --> Add a payment method to your Apple Account - Apple Support
- Add money to your Apple Account balance - "Use a payment method, such as a credit or debit card, to add funds to your Apple A balance." This takes the previous payment method one step farther by optionally using it to irreversibly add funds to an Apple Account balance instead of having the card charged each time.
Click here --> Add money to your Apple Account balance - Apple Support
If no option is shown to "Add Money to Account" using this method (you only see using gift cards) then it may not be available in your country. Use a gift card instead.
- This article outlines how to redeem an Apple Gift Card or App Store & iTunes gift card --> How to redeem your Apple Gift Card, App Store Card, or App Store & iTunes Gift Card - Apple Support
You could also look into joining a Family Sharing group where the Family Organizer's payment method is used. To learn how to join a Family Sharing group, read the section "Join a family group" in the document "Set up Family Sharing". This link will take you straight there --> How to set up Family Sharing on your iPhone, iPad, or Mac - Apple Support
By the way, Apple does not respond to questions on this forum. We are users like you. I have never seen anybody say that Apple will let you continue to purchase if you owe them money and they insist you pay what you owe first.
