When you provide your discount code to your customers, they can enter it in the Discount Code field at the bottom of the cart display.
Enter the discount code and press Apply. The name and the amount of the discount will appear above the Subtotal..
Discount codes can also be entered from the checkout page. The option appears as Promo code in the Order Summary section of the checkout process.
Click Add a promo code, enter the discount code in the Promo code field, and click Apply.
If the customer applies a coupon code here or on the cart summary, they'll have the option to remove it here by pressing X next to the discount.
The rest of the checkout process proceeds normally.
At this time, customers can apply a maximum of one coupon code per order.