on Pay Invoice
Called when the user presses the buy button.
The extractions were updated to contain the user's modifications:
"amountToPay" was updated to contain the sum of the selected line items' prices,
the line items were updated according to the user's modifications.
Parameters
specificExtractions
extractions like the "amountToPay", "iban", etc.
compoundExtractions
extractions like the "lineItems"