had same issue - Apple Pay not live on Stripe side although enabled on Shopify side.
Contacted Stripe support and they solved the problem in 15 mins.
Main issue: enabling Apple Pay with Stripe on a Shopify store, particularly Stripe’s requirement to verify the merchant domain by hosting Apple’s association file at https://yourdomain/.well-known/apple-developer-merchantid-domain-association.
What works for many: ticking Apple Pay in Shopify admin (Settings > Payments, edit provider) appears sufficient, and Apple Pay only shows on Safari and Apple devices. Some checkout errors resolved without a clear fix after support review or simply retesting.
Key blocker: Stripe sometimes enforces domain verification. Shopify’s Files tool returns a cdn.shopify.com URL, which does not meet the strict path requirement at the root domain.
Attempts and suggestions:
Edge case: Apple Pay blocked due to product category (pseudo‑pharmaceutical) per Apple/Stripe policies.
Status: No definitive Shopify-native method to host the required file at /.well-known on a Shopify-hosted domain. Discussion remains open; latest posts still seeking a solution without separate hosting. Screenshots referenced Stripe’s verification prompt and Shopify payment settings.