The confirmation number is a nine-digit number that you will be notified of after purchasing a domestic flight ticket.
It is also included in the payment completion email and in the notification emails provided 24 hours and 2 hours before the departure time of the reserved flight.
This is the authorization code you will need when boarding, when changing your reservation, and when receiving or refunding your ticket.
Please write it down together with your reservation number and take sufficient care to manage it.