The "checkout" button on the product page has three options.
STEP 2: Redeem
Click "Show order summary",Enter the discount code
STEP 3: Finish
Discount applied, proceed to payment.
Choosing a selection results in a full page refresh.
Opens in a new window.
 
 
One or more of the items in your cart is a recurring or deferred purchase. By continuing, I agree to the cancellation policy and authorize you to charge my payment method at the prices, frequency and dates listed on this page until my order is fulfilled or I cancel, if permitted.