In the left menu select Portals/CMS and click on the Joomla option.
Click the blue Install button.
Choose the latest version of Joomla if you’re unsure of which one to choose here.
Fill out the form as required; ensure you select your Choose Domain and In Directory options correctly - In Directory should be empty unless you want the site on a separate page.
Ensure you set a strong admin password (greater than 60 strength).
Click Install.
That’s it! The app installer will now install Joomla for you and then provide you with links to access its admin area.