When checking out on Amazon with a promotional code, simply put the products the code or codes apply to in your cart and check out. When prompted, input the code you received and click Apply.
After placing all the items you desire in your cart and clicking the Proceed to Checkout button, you are prompted to update your shipping address and payment method on the Place Your Order page. In the field for entering the payment method, there is a small box for using a promotional claim code. Carefully put in your code and click Apply. The code's discount is applied to your order and appears in the Order Summary on the right side of the page.
Make sure that all the items necessary for the code's use are in your cart when you check out; free items are not added to your cart automatically when you input your code. Taxes, gift wrap, and shipping and handling charges do not apply toward any minimum purchase amount required for the code.
You can only use each code once. If you are shipping your items to more than one address, your items are split into separate orders and the code only applies to one of them.