iTunes gift cards
Can I use a iTunes gift card to buy stuff on another online website?
iPhone 11, iOS 13
Question marked as
No. According to: Redeem App Store & iTunes Gift Cards and content codes - Apple Support
"What you can buy with a gift card
When you redeem an App Store & iTunes Gift Card, you add credit to your Apple ID balance. You can use that credit to make purchases in the App Store, iTunes Store, Apple TV app, or Apple Books. Or you can use the credit to upgrade your iCloud storage or pay for subscriptions like Apple Music, Apple Arcade, Apple TV+, Apple TV channels, or Apple News+.
You can’t use your credit to buy gifts for someone else or buy more gift cards. You also can’t share credit with family members, even if you use Family Sharing."