This version of the link will take you to the section of the support article about what to do if your code is unreadable —> https://support.apple.com/108285#unreadable:~:text=If%20your%20gift%20card%20code%20is%20unreadable
If you can't read the code on the back of your card because it's scratched or damaged, contact Apple Support using this special link —>
https://getsupport.apple.com/?caller=kbase&PGF=PGF63003&category_id=SC0082&symptom_id=20256 then click "Get more help"
You might need to provide:
• An image of the full front and back of your card.
• A sales receipt showing when your card was purchased.
• The serial number from your card (serial numbers are located on the back of your card underneath the bar code).