You can use your discount code only during the booking process. When you are filling out your personal details, click on ‘Apply discount code’ and fill it out. A discount code can only be used once, can only be used on the same profile and is always bound by specific conditions. Because of this, your discount code may not be valid on the selected flights.

Discount codes are never valid for bookings via websites like Skyscanner, Momondo, Kayak, etc.