When create sales invoice unit price column should not empty except is FOC item

Scenario: 

When create Sales invoice, request user must not let the unit price column empty but at the same time have stock as Free Gift which is 0 amount, how to do the setting? 

Solution: 

How to Access Customization Centre:

https://support.qne.com.my/support/solutions/articles/81000383848-how-to-access-customization-centre 

1) Go to Customization Centre > double click QNE Optimum 

2) Model > Validation > Rules > QnEBS.BO.Sales.SalesInvoiceDetails > right click and clone the selected that show

3) After clone, follow below screen

Remark: CustomMessageTemplate is to show what error message should prompt 

4) After the setting > Save > Close > Logout and login system again to test create sales invoice with unit price = 0 and will show error message

Result:

For Free Gift which the amount is 0 still able to save 

** Learn more about Azure Cloud

** Learn more about QNE Hybrid Cloud Software

Refer attachment for details