You can do this on the checkout page.
- Enter your email address.
- Select the Promo code checkbox.

- Type in the code, then click Apply.

- If the code was for a free copy, you will be able to complete the purchase and watch it immediately. If the code was for a discount, you will need to enter your payment info to complete the payment.
Please note that at this time, coupons can only be redeemed if you’re paying in USD.