Apple gift card

Yes, it is possible based on this Apple article:  -> What you can buy with your Apple Gift Card or Apple Account balance

• Buy music, movies, and more from the iTunes Store, Apple TV app, or Apple Books.

When redeeming a gift card, the amount will be credited to your (1) Apple ID balance and (2) you need to set your Apple ID balance as your default payment.

1.

See -> Check your Apple ID balance

Check your Apple ID balance – Apple Support (UK)

(2)

Change, add or remove Apple ID payment methods

Change, add or remove Apple ID payment methods – Apple Support (UK)

If you update your payment method or add funds to your Apple ID balance, It would take about 1 to 3 business days in order to process.

If you're still unable to update your payment method, Contact Apple Support.

Where to buy a physical Apple gift card:

Actually, you can buy an Apple gift card at many places, it depends of course on where you live.

At an Apple Store or an Apple Authorized Reseller in your region certainly, but also at a good bookstore, supermarket and/or drugstore.

Be alert for -> About Gift Card Scams -> About Gift Card Scams - Official Apple Support 

Click here for more support and assistance.