Store gift card

From: Check your Apple ID balance - https://support.apple.com/HT202359 -->

"About unused Apple ID balance

You can't redeem or return Apple Gift Cards, App Store & iTunes Gift Cards, or unused Apple ID balance for cash, except as required by law. If your jurisdiction allows for refund of redeemed gift balances, you can contact Apple Support."

A Community Specialist in this topic --> https://discussions.apple.com/thread/253337931 recommends contacting Apple about your options:

Click here --> https://support.apple.com/choose-country-region/media-services Select your country, then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

Contact Apple for support and service --> "See a list of Apple phone numbers around the world."

Click here --> https://support.apple.com/HT201232

Along these lines, what you can do with the card depends upon the type of card. This article explains the different kinds of gift cards Apple uses and has links on how to redeem them and what can be purchased with each kind. Click on the link --> What type of gift card do I have? - https://support.apple.com/HT204199

When you choose to redeem the gift card, you can use it on any Apple purchase. 