By creating a new sandbox, the user can have a dedicated installation on which he/she can customize the settings depending on his/her needs.
Each applied change to the theme and/or plugin settings will be defined within the sandbox environment and will not entail any change in the parent installation.
Before all, you need to ensure that the “Allow New Sandboxes” option is enabled.
Now, in order to create a new sandbox, click on the “Launch Admin Demo” button added to the topbar provided by the plugin.

After clicking on the button, a new sandbox will be automatically created and the user will be redirected to the new installation back-end.
The user has access to the sandbox with the same role you have set in the “Demo User Role” entry of the plugin.

The user will be automatically removed when the sandbox expires.
Please note: the user cannot create two sandboxes for the same site at the same time. Until his/her sandbox is active, he/she will be automatically redirected to the current sandbox when he/she tries to create a new one for the same site.