Access the settings
Enter the PC Server menu → Setting → Point of sale → Discounts.
To create a discount click on New, complete the Detail field and the Discount Amount, and finally click on Ok.
Discounts can be a fixed value, for example $1, or a percentage value, for example 5%, by ticking the Is percent option.
If you want to edit any of your discounts, double click on it to access the edition.
Select the discount you want to remove, press Delete and confirm the action.
Discounts is a Permissions configurable by operator.