Looking for help on our stock system. We use serial numbers to track products. Just got the delivery note & material transfer sorted out. How do I create an invoice that includes; patient name & office (the same ‘warehouse’ the serial number will be in, as well as serial number & batch. Tried creating through customer first & then adding an invoice, but error code “AttributeError: 'PosnextSalesInvoice” object has no attribute ‘service_unit’ Possible source of error: healthcare (app). Need the serial number to pull out from customer warehouse when invoice is created.