I cannot redeem code

I can't answer that question, but If you need more help, contact us." states:

"If you still can't redeem your card or code, or the code on the back of the card is completely scratched off, contact Apple Support. Apple Support can provide help, but you might still need to contact the retailer the card was originally purchased from.

Please be prepared 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. "

According to: If you can't redeem your App Store & iTunes Gift Card, Apple Music Gift Card, or content code - Apple Support

"Card or code is inactive

If you see a message that your card is inactive, it might not have been properly activated. The best option is to go back to the retailer where you purchased it and try to resolve it with them.

If you need more help, contact us."

You are welcome.