Can I use Apple Pay for in-app purchases?

Yes. You can use Apple Pay to pay within apps, when you see Apple Pay as a payment option with either of these purchase buttons:

At check out, tap the Apple Pay button or choose Apple Pay as the payment method. Check billing, shipping, and contact information to make sure that they are correct. If you want to pay with a different card, tap (>) next to the card. If you need to enter billing, and contact information on your iPhone or iPad, Apple Pay will store that information, so you will not need to enter it again. Confirm the payment. When the payment is successful, you will see Done and a checkmark on the screen.

• iPhone or iPad with Face ID: Double-click the side button, then use Face ID or passcode
• iPhone or iPad without Face ID: Use Touch ID or passcode.
• Apple Watch: Double-click the side button