i mistakenly scratched off the first 6 numbers on my apple gift card

Please follow the steps in this Apple Support article. 

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

If after reviewing the article, and following the directions in the article, you need additional assistance please follow the link below to contact official Apple Support. 

Contact Apple Gift Card Support

Yes, tap the link in my post above and in the email you received that says Contact Apple Gift Card Support. Here’s the link again for your convenience.

Contact Apple Gift Card Support

Try holding your finger on the link and select Open or Open in New Tab and then scroll down.