Softaculous is software that auto-installs web applications with one click. There is a wide range of web applications, CMS, Web-portals, E-commerce solutions, Scripts, etc. that can be installed with one click easily.
Installing Softaculous is very easy, and it can be completed in just a few clicks. So let's begin the installation of Softaculous on Plesk.
Step 1: Open Plesk in your web browser and log in with the root user.

Step 2: Now, go to the "Server Management -> Extensions" page and click on the "Extensions Catalog."
Here you can browse and install various extensions available for Plesk.

Step 3: In the search bar at the top of the catalog, type “Softaculous” and press Enter. The Softaculous Auto Installer extension will appear in the results.

Step 4: Click on the "Install" button next to Softaculous. The installation process will take a few moments, depending on your server speed.

That's it, we have successfully installed Sofaculous. You can find it under the "My Extensions" tab.
Please note that the free version of Softaculous is installed by default. In case you need the full license for Softaculous, please submit a support ticket.