How to get postalAddress prior to displaying Payment Sheet in Apple Pay

I am trying to get the PKContactField.postalAddress prior to displaying the Payment Sheet so that I can use the postalCode to calculate taxes. I've found examples on how to get the information after the user has selected the billing details from the payment sheet but I can't figure out how to get it before. I have included the requiredBillingFields = [.postalAddress, .name] and it is displaying on the payment sheet. It looks like I should be able to get it from the ApplePayContactField prior to displaying the payment sheet but I can't figure out how to implement.

Checkout the Apple Pay on the Web Demo in the section for Requesting a Shipping Address. Now, I realize that this documentation describes the Shipping contact information, but I believe the same rules apply for requiredBillingFields. Only limited information will be provided until the user authenticates the transaction.

Matt Eaton
DTS Engineering, CoreOS
meaton3@apple.com
How to get postalAddress prior to displaying Payment Sheet in Apple Pay
 
 
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