How to access shippingContact after transaction?

So I know I can request for an email in the paymentRequest requiredShippingContactFields and could also access minimal information with onshippingcontactselected, but how can I actually get the full shippingContact AFTER a transaction. The documentation doesn't say what API call this is returned with or anything, so please help!

Relevant doc: https://developer.apple.com/documentation/apple_pay_on_the_web/applepaypayment/1916097-shippingcontact

How to access shippingContact after transaction?
 
 
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