Which information is required when adding a device to Firepower Management Center?

 When adding a device to Firepower Management Center, you need to provide a registration key, which is a unique alphanumeric string that you create and enter on both the device and the Firepower Management Center. The registration key is used to authenticate the device and the Firepower Management Center to each other. You do not need to provide the username and password, encryption method, or device serial number when adding a device to Firepower Management Center1. References: 1: How to Manage a Device with the Firepower Management Center - Configure the Managed Device