Add a voucher payment to an order

Redeem a voucher code against the order. The voucher's remaining balance is applied as a payment against the order — either settling the outstanding balance in full or contributing toward it depending on the voucher's value. The order is returned with the new payment listed in its payments array.

The voucher code must reference a valid, unredeemed VoucherCode on the order's site. Common failure modes:

• 400 Bad Request — the voucher is expired, fully redeemed, belongs to a different site, or is in a state that doesn't accept new redemptions. The error message describes the specific reason.

Remove a previously-redeemed voucher with DELETE /shop/orders/{orderId}/vouchers/{voucherCode}.