Make sure you are registered in TSA PreCheck and have a Known Traveler Number (KTN) before adding TSA PreCheck to your Japan Airlines (JAL) reservation. How To Add TSA Precheck To Japan Airlines Next, access your reservation on the Japan Airlines website or enter into your JAL account. Locate the opportunity to add your KTN by navigating to the passenger details area. After entering your KTN in the appropriate field, save the modifications. For help, get in touch with JAL customer care if you are unable to locate this option. When you get to the airport, make sure your boarding pass has the TSA PreCheck emblem on it.