How can I apply for TSA PreCheck and what is the process to get TSA PreCheck approval?

To apply for TSA PreCheck, you need to complete an online application, schedule an in-person appointment at an enrollment center, and provide required documentation such as a valid ID and proof of citizenship. During the appointment, you will be fingerprinted and undergo a background check. If approved, you will receive a Known Traveler Number (KTN) which you can use when booking flights to access TSA PreCheck lanes at airports.