The device has 2 different user groups: (a) the Administrator, who can access the device's menu, and (b) Normal users who can punch in/out of their shifts. Note, that the Administrator needs to be set up before all other users.
When you first start using your facial scanner the Administrator (normally your Site Manager) will register all other staff as Normal users. When new staff on-boards the Administrator will also register the new staff member on the device.
This video provides a brief step by step guide for the registration of Normal users.