If you are using the most recent version of Audacity the plug-in folder is here …
C:\Users\<YourNameHere>\AppData\Roaming\audacity\Plug-Ins
After you put a copy of the “.ny” plug-in files into that folder you have to enable them in the plug-in manager before they appear on the Effects menu.
Remember to click on the “OK” button below the “Enable” button to make the changes stick.
Yes that’s another Audacity plugin, you can get a copy here … USB Whine FIltering (Yeti Curse) - #35 by kozikowski
“mosquito” is the whiny high-pitched computer-generated noise.