post
https://apis.kentro.live/store/v1/invoices.pay
Pays the open balance of an invoice (id) with a saved card or bank account (paymentId), once per idempotencyKey. expectedAmount is the total the buyer was shown (invoices.get payment.methods[].total, fee included); a balance that changed since is refused. A bank account needs bankConsent: true and the payer's userAgent. Follow a confirming or processing answer with invoices.paymentStatus.
Who may call it: A signed-in buyer (X-Storefront-Buyer) whose account is confirmed (session.get answers confirmed: true); an unconfirmed buyer is refused with 403 CONFIRMATION_REQUIRED.
