create the directory UserAppData/Mod/plugins
download the zipfile of the complete project to your computer.
unzip it - you will get a directotry freecad-pluginloader-master
move the content of this directory into UserAppData/Mod/plugins
you can modify this file if you want: pluginloaderconfig.yaml
You can also use this script, it makes the same:
https://raw.githubusercontent.com/microelly2/freecad-pluginloader/master/installer.py
Copy and paste into the FreeCAD python comsole window
It works on Linux.
start FreeCAD
A dockwindow will arise may be hidden, you can open it Menu View -> Views -> Pluginmanager
The bottom item starts the installer dialog
Select the plugins you want to install
Click Button install/update
The configruation file is .FreeCAD/Mod/plugins/pluginloaderconfig.yaml
Section plugins
For each plugin create a subsection with its name.
required attributes:
source
sourcedir
destdir