This setting is Cart & NetSuite specific and may or may not be available to on your Cart / NetSuite Platform.
Step 1: Open Unify Desktop and "go to File >> Configure Store >> Discounts screen."
Step 2: Choose your discount item from NetSuite and click on 'Save'.
If the Item is not visible / not created in NetSuite, follow the steps below:
Step 1: Open the 'Item list' in NetSuite and create a new item of type 'Discount'.
Step 2: Click the 'refresh' icon in the Unify Desktop's Discount configuration area to bring in the new details from NetSuite and then choose your 'discount item' from NetSuite and click on 'Save'.