The first thing to do to have Antares Autotune VST into Audacity is to actually install the library on your PC using the setup.exe file.
After it's installed, locate its folder and copy the Auto-Tune_EVO_VST.dll and AutoTuneVST.dll and restart Audacity. Go to Effects > Add/Remove Plug-ins and make sure the Autotune is enabled. Then return to the Effects and activate the plug-in.
