If you have several employees in your company, they can log on and off at all cash registers. To do this, click on the "Logout" button in the main view at the bottom right-hand side of the screen.
The login screen appears, in which you have to enter the "Employee PIN" in order to log on to the system.
You can assign the "Employee PIN" individually. A detailed description of how to create employees can be found here: Create employee.