Part 3: Perform Additional Setup for Apple Pay on the Web

If you develop web pages that support Apple Pay on the Web, your customers can use Apple Pay to purchase goods and services from within your web page. You can use the same Apple Pay merchant ID and Apple Pay payment processing certificate as required for Apple Pay in-app implementations. However, Apple Pay on the Web requires additional set-up tasks that you perform in your Apple Developer account:

Creating an Apple Pay merchant identity certificate
Registering your merchant domains with Apple

If you created multiple merchant ID and payment processing certificate pairs to support multiple environments, such as sandbox and production, you must associate each ID-and-certificate pair with a unique merchant identify certificate.