From there, depending on where you intend to implement Apple Pay – on your iOS app or on your website, or both – the setup process will be different.
If you plan to add Apple Pay to both an iOS app and your website, complete each process below.
To set up Apple Pay on your iOS application:
From the Apple Pay settings page, click + Add new application.
Download the Certificate Signing Request (CSR) and click Continue.
Visit Apple’s Developer Center.
Select the Merchant ID the certificate should belong to, then click edit and create certificate.
Disregard the directions for creating or obtaining a CSR file; this is the Certificate Signing Request file you downloaded earlier from Stripe.
Follow the instructions to upload your CSR file.
Click generate to generate a certificate, and download the certificate. The certificate should be in the .cer file format.
Return to Stripe and upload the new certificate file:
Once uploaded, you should see the certificate listed under iOS certificates.
You can then continue with integrating Apple Pay for apps.
To set up Apple Pay to integrate into your website:
From the Apple Pay settings page, click + Add new domain.
Enter the top-level domain or sub-domain where you will be implementing Apple Pay (e.g. stripe.com or shop.stripe.com).
Download the verification file: this will be a text file titled apple-developer-merchantid-domain-association.
Upload the verification file to your website at the URL you entered in step two. The resulting URL should look like https://yourwebsite.com/.well-known/apple-developer-merchantid-domain-association.
You can then continue with integrating Apple Pay for the Web.