Hi - I'm currently implementing Apple Pay in a native app using the PassKit APIs.
I'm unsure as to whether it is mandatory to implement the paymentAuthorizationControllerDidRequestMerchantSessionUpdate delegate method to return a PKPaymentRequestMerchantSessionUpdate (which I believe would involve our backend service requesting a merchant session JSON object from Apple Pay servers).
From all my tests on an iOS device so far, this delegate method is only ever called if we don't set a merchantId in the PKPaymentRequest. Since we always set that value, this should never arise.
The WWDC 2020 talk which introduces it only mentions it in the context of Catalyst or macOS native apps. Does this mean that the method does not need to be implemented for iOS-only apps?
In other words will our payments sometimes fail on iOS if we don't implement this delegate method?
Anyone had any experience of implementing this? The official documentation is very sparse and 99% of examples seem to be talking about the Apple Pay for JS API, which uses the merchant session as an explicit part of the sequence, rather than the PassKit APIs.
Thanks in advance.