How can I redeemed my Apple Card?
How can I redeemed my Apple Card with serial number
[Re-Titled by Moderator]
See -> How to redeem your Apple Gift Card or App Store & iTunes gift card
How to redeem your Apple Gift Card or App Store & iTunes Gift Card – Apple Support (UK)
When redeeming a gift card, the amount will be credited to your Apple Account balance and you need to set your Apple ID balance as your default payment.