Open profile settings by clicking Browser Settings button on the ribbon.

Select the profile you want to configure and proper command line parameter.

For Chrome specify

--incognito

For Firefox

-private

For IE

-private

How it works. When Rapise launches a test, if required browser is not opened yet Rapise uses profile settings to launch a new process with specified command line parameters .

Also a test can explicitly open a browser with specified URL.  If in this case browser is not running yet  then profile settings are also used to start it.

Navigator.Open("http://libraryinformationsystem.org");