How do I navigate common errors when adding Apple Pay to my merchant account in Customer Area?

Solutions to common errors

If you are encountering errors when adding Apple Pay to your merchant account in the Adyen Customer Area, please try the following solutions. 
Note: It is not necessary to host a domain association file for TEST.

Make sure the URL does not have a “/” at the end. This also applies to TEST.

• https://my-checkout.com/ ❌
• https://my-checkout.com  ✅

Make sure you host the domain on a static URL, dynamic URLs won’t work.

• If you process payments on:
  • https://my-checkout.com/nl/home/checkout  ❌
  • https://my-checkout.com/en/home/checkout ❌
• The file needs to be: 
  • https://my-checkout.com/.well-known/apple-developer-merchantid-domain-association.
• The URL you use to add ApplePay from the Customer Area will be: 
  • https://my-checkout.com ✅

Check that the following IP addresses have been added to your firewall’s allow list:

• Allow Apple IP Addresses for Domain Verification
• Any IP originating from *.adyen.com

Check that the domain association file has been hosted correctly. 

You can see an example of a working domain association file hosted on https://eu.adyen.link

To verify the contents of the file, you can use the cksum binary. Instead of eu.adyen.link/, use your own URL:: 
curl -s https://eu.adyen.link/.well-known/apple-developer-merchantid-domain-association | cksum
The output of the above, is: 2304607924 9094
If the file hosted is the correct file. The cksum output will be identical to the reference file: https://eu.adyen.link/.well-known/apple-developer-merchantid-domain-association. Any deviation from the above suggests that there's something wrong with the file.