For tickets purchased 24 hours prior to scheduled departure, all flights can be canceled within 24 hours of booking for a full refund.
Alaska Airlines Cancellation Policy says for tickets purchased more than 24 hours prior to scheduled departure, Main Cabin and First Class fares may be changed within 24 hours of reservation without a change fee (but you will be responsible for any fare price or tax increase). Saver fares cannot be changed up to 24 hours prior to departure but can be canceled or rebooked within 24 hours of booking.
If you purchased a refundable ticket, you can request a refund online or by contacting a customer service representative using your original payment method.
Excluding saver rates, you can cancel or change your reservation until the flight departure. If you have booked a non-refundable ticket and want to cancel, you will receive credit for a future flight.
If you do not qualify for a refund, you are allowed to cancel your reservation and use an amount equal to its value for future travel.
If you purchased your ticket from a third party, such as a travel agent or an online website such as Skyscanner / Expedia, you should contact them directly to process your cancellation request.
Cash purchases will be refunded within 20 working days and credit card purchases will be processed within 7 working days but may take up to 14 days to reflect on your account.