Many passengers ask How To Add TSA Precheck To Lufthansa Airlines? Make sure your Known Traveler Number (KTN) is active before adding TSA PreCheck to your Lufthansa reservation. Go to your profile or booking information after logging into your Lufthansa account. In the passenger information section, enter your KTN. To be eligible for TSA PreCheck, you must provide your KTN while making a reservation over the phone or through an agent. Â