As well as specifying the Child Object, you must specify fields on that Child Object. Most fields are optional, and QBO requires a Product/Service in every line item.
Also, please note that the field types must match. You must use a Date (or Date/Time which will be converted into a Date transparently) for the Service Date field. Quantity and Unit Price are number fields (we accept up to 7 decimal places) and QBO’s Taxable field must be a Checkbox/ Boolean.
For Picklist fields (Classes in QBO) you must use fields that match, exactly, case-sensitive to existing fields in your Accounting System. If we cannot find an exact match in your accounting system we ignore those fields.
If the QBO Product/Service, also known as the QBO Inventory item (as specified by the child_object_inventory_name) does not exist in QBO as an Inventory Item, the user will be prompted to either create it or to use an existing Inventory Item for that invoice creation.
Also, be aware that for QBO, Service Date and Classes has to be explicitly enabled in QBO Setup before Breadwinner can populate them. We cannot add new values to any of these; we are limited to populating these fields with values already in the accounting package.
The Line Item Tax Code is available only for the QuickBooks Non-US Orgs. You can optionally populate the Line Item Tax Code using the Child object’s field. If you pass the field API name to the child_object_taxcode param, Breadwinner will show this field value on the Line Item Tax Code while creating the Invoice.
The Line Item Inventory Site is available only for the QuickBooks Desktop. You can optionally populate the “Inventory Site” using the Child object’s field. If you pass the field API name to the child_object_inventorysite param, Breadwinner will show this field value on the Line Item Site while creating the Invoice.
Note: Inventory Site setting should be enabled in the QuickBooks Desktop to populate the Inventory Site value using Breadwinner CURL