I open WHM, go to Plugings and open - Softaculous - Instant Installs
Softaculous opens in a new window, there I go to Software - General Scripts and select Freescout (the script I want) - there I check the 'Install' checkmark and press on the 'update settings' button on top of the page. Then it showed it was updating the files and that the settings where changes successfully.
After that I go back to WHM, and search for 'Freescout' - but it does not show up at Plugins.