Add Discount & Extra charge
From Protemos Wiki
To add a discount and(or) an extra charge to a payable, click on the payable code:
It will open the payable details page.
Press the "Discount & Extra charge" button:
Enter the required value and press "Update" to apply changes:
To add the discount and extra charge, you can also click on the "Update" button in the payable row:
And then press the "Discount & Extra charge" button on the opened update page: