To enable Apple Pay on your custom paywall (without Stripe Checkout), you must verify your merchant domains by uploading a verification file.
Verification Process:
Prepare your domain according to Apple's specifications:
Reference: Apple's Domain Verification Documentation
Upload the verification file:
Navigate to your Project Overview page in Onboarding.online
Make sure your custom domain is verified.
Locate the "Apple Pay Web Merchant Registration" section
Click the "Upload" button to submit your verification file