If you need to cancel your Alaska Airlines flight, you can do so online, over the phone, or at the airport. The airline allows free cancellation within 24 hours of booking, provided the reservation was made at least two days before the departure date. After 24 hours, a cancellation fee may apply, depending on the fare type, destination, and time of cancellation. Passengers can cancel their flights up to 60 minutes before the scheduled departure time.
Read the complete information here: Alaska Airlines Cancellation Policy