In order to enable Order Level Discounts By Role in your store navigate to Discounts Setup screen from the Store Admin Menu and
In order to enable Product Variant Quantity Discounts in your store navigate to Discounts Setup screen from the Store Admin Menu and select the radio button option titled “Enable Product Quantity Discounts” as depicted in the following screen shot:
For more information on the Discount Setup screen, please see the Discount Setup section.
Next, the Variant Quantity Discount Setup needs to be configured. To configure the Variant Quantity Discount screen, please see the Variant Quantity Discount Setup section for more information.