Click on the link that I posted. Here it is for a third time: https://forum.audacityteam.org/t/silent-subliminals-solved/20100/1
That will take you to a forum post where there is a link to the plug-in.
Click on the download link for the plug-in:
Instructions to install the plug-in are here: http://wiki.audacityteam.org/wiki/Download_Nyquist_Plugins#install