Many travelers are curious about 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 details after logging into your Lufthansa account. In the passenger information section, enter your KTN. To be eligible for TSA PreCheck, give your KTN while making a reservation over the phone or through an agent.