In the application's main menu, select Anti-theft. In the Configuration Wizard window, enter and confirm a password. If necessary, create a friends list (a list of trusted numbers).
More detailed information about configuring the anti-theft can be found in the corresponding section of the documentation.
Then you can adjust anti-theft security parameters: set blocking conditions and the actions that the program will perform if those conditions are met. More information about this can be found here.
To activate the anti-theft, use the previously specified password.