How to install Plesk additional components (like Backup Manager, PHP etc.) with autoinstaller?
Plesk Control panel->tools and Settings->Updates and Upgrades button. Please make sure that port 8447 is opened. It is used by autoinstaller, please refer to this article for information at (Updates and Upgrades page cannot be opened: it just loads continuously I have already written).
Login to the server by SSH and launch autoinstaller:
Just follow instruction on the screen and you will be able to install additional components.