Can I use the gift card sent to my mailbox in physical store?

Hi 奕材,

Just to confirm, what type of gift card do you have? We ask because you can use an Apple Gift Card to purchase products or accessories at an Apple Store.

Please check out this link, which has more information about what you can buy with your Apple Gift Card, and may help: What you can buy with your Apple Gift Card or Apple Account balance

What you can buy

You can use Apple Gift Card to purchase products or accessories at an Apple Store.

In countries and regions where Apple Gift Card is available, you can use your Apple Account balance to buy products and accessories at apple.com or in the Apple Store app. In these countries and regions, your Apple Account balance includes the balance from any Apple Gift Cards or App Store & iTunes Gift Cards that you have redeemed.

Thanks!