How do I add my MasterCard gift card to Apple

Hey there Fiona1029,

Thanks for reaching out to Apple Support Communities. It sounds like you’re having some issues adding your gift card to iTunes. I’ll be happy to help.

‘You can typically use these methods with your Apple ID:

• Apple Pay (where available)
• Most credit and debit cards
• Store credit, from redeeming gift cards or from adding funds to your Apple ID’

There are also country-specific or region-specific additional methods as well. You can read more about these here:

Payment methods that you can use with your Apple ID

This article tells you more about the gift cards accepted with the App Store and iTunes:

Redeem App Store & iTunes Gift Cards and content codes 

I hope this helps.