The author rightfully recommends %HOMEPATH%\AppData\Roaming\GIMP\2.10\plug-ins\ (so C:\Users\{your id}\AppData\Roaming\GIMP\2.10\plug-ins\, usually) but that shouldn't make a difference.
Have you got a Python installed in your system (in addition to the one that comes with Gimp)?
Have you got a Python installed in your system (in addition to the one that comes with Gimp)?