How do you get user consent for ConsumptionRequest?

https://developer.apple.com/documentation/appstoreserverapi/send_consumption_information

If the customer provided consent, respond by calling this API and sending the consumption data in the ConsumptionRequest to the App Store. If not, respond by calling this API and setting the customerConsented value to false in the ConsumptionRequest; don't send any other information.

Since our server would be receiving CONSUMPTION_REQUEST server notifications and will be the one calling the Consumption API, how do we know if the user has provided consent? That info doesn't seem to be in the server notification or anywhere else.