I mistakenly scratched off part of the code on my Apple Gift Card

Follow the steps here for when your code is unreadable.

If you can't redeem your Apple Gift Card, App Store Card, or App Store & iTunes Gift Card - Apple Support

Since this is a site open to the public, it is not wise to post a picture of your card here as stated on the card where it says: Do not share your code. Anyone can try guessing a number of combinations and you will be without the money on the card.