Select your desired product.
Hit click on Buy now option then go to checkout.
Fill your personal information in Shipping Information portion and save it.
After saving your personal information click next icon which is on the bottom of the page.
After clicking on next icon, you will have the payment portion and coupon bar.
Enter the Coupon Number correctly
After you enter the coupon number correctly, you go down to final payment; the amount of coupon will be deducted from the total bill.
At end, you have thank you message