we have added a custom field in our NetSuite instance called custbody_billing_platform which is associated to a list. I want to have snaplogic update the invoice header with the appropriate internalId of the list. on all other netsuite snaps for object updates the fields appear in the snaplogic snap under Cust Field. for some reason the custom field associated to the invoice (which I am learning the field is at the transaction level yet available within NetSuite on the Invoice) does not show in the dropdown like it does for other custom fields. this is consistent with the Invoice object in NetSuite b/c we have many custom fields yet they do not show. how do we update custom invoice fields via snaplogic in this case?