Apple gift card to use Apple pay

You can use an Apple Gift Card to purchase a book from Apple Books, or music or apps from Apple.

You cannot use an Apple Gift Card ro purchase from another firm.

Kindle books are purchased from Amazon.

Amazon is not Apple.

No.

You cannot use an Apple Gift Card to purchase a Kindle book.

Gift Cards are limited to purchasing products or services or apps or media from Apple, and not for transferring money to others.