authenticationToken (required)(string:20): Komet Sales security token.
invoiceId (required)(integer:20): the Komet Sales invoice internal ID that you want to update. You can obtain this value from the invoice.create API method.
invoiceItemId (required)(number:20): ID of the Komet Sales invoice item. This value can be obtained from the invoice.create API method.
boxes (optional)(integer:10): new number of boxes.
If the customer for who you are editing an invoice has a different currency, you should enter prices in your customer's currency and the system will generate the invoice in your company's currency, based on the exchange rate set up at the time of the transaction.