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.