Transaction fails with Payment Not Completed error for a sample merchant account with utf8 character in the displayName at completeMerchantValidation step.

I read the documentation,

A string of 64 or fewer UTF-8 characters containing the canonical name for your store, suitable for display. This needs to remain a consistent value for the store and shouldn’t contain dynamic values such as incrementing order numbers. Don’t localize the name. Use only characters from the supported character sets in the fonts listed in the table below.

ref : Request Parameters

how we are invoking the completeMerchantValidation()

session.completeMerchantValidation({
  displayName: 'じゃ', //utf-8 string
  //... other params as per the docs
})

Note: if the displayName is in english, it works.

As suggested in Apple Pay on the Web Debugging Guide, When I checked PassKit log, I could see Payment failed with fatal error in logs but not clear pointers on why.

Error com.apple.PassKit.PaymentAuthorizationUIExtension: (PassKitMacHelper) [com.apple.passkit:PaymentUI] Payment failed with fatal error