Ascertain that you have a Known Traveler Number before adding TSA PreCheck to your Japan Airlines reservation. To access your reservation, log into your JAL account. Once you have chosen Manage Booking, How To Add Tsa Precheck To Japan Airlines find the passenger details area. You can enter your KTN there. You can also present your KTN at the airport check-in counter or contact JAL customer support for assistance if you forgot to add it when you made your reservation. For a seamless screening experience, make sure the name on your JAL reservation corresponds to the name linked to your TSA PreCheck membership.