How to manually install addons
In explorer, paste this to the address bar:
For Blender 3.6
%appdata%\Blender Foundation\Blender\3.6\scripts\addons\
For Blender 4.5 (extension platform)
%appdata%\Blender Foundation\Blender\4.5\extensions\user_default\
Then, extract the addon zip file and move the contents to the addon folder.