You may enable the Automatic System Shutdown setting at the
checkbox in the Advanced Settings tab in the main window.

Alternatively, you may enable the option with the following command
line argument:
-
Many users prefer to run the system backup operation at
the end of the day. Since XXCLONE operation may take
some time, you may not want to wait for the completion
of the full XXCLONE operation.
-
When this setting is enabled, XXCLONE will initiate
the system shutdown operation at the end of its operation.