Audacity is a free, open-source, cross-platform (compatible with both macOS and Windows) audio software.
To load the newly installed Voice Changer plug-in within Audacity, please follow the steps below:
1) Open a new project in Audacity
2) Go to Effect > Add/Remove Plug-ins
3) On the new window, Plug-in Manager: Effects, Generators and Analyzers, find Voice Changer VST in the list
4) Once you find the plug-ins you need, select them and press the Enable button
4) Press OK to close the window
5) Select the track you want to process and again go to Effect > Add/Remove Plug-ins. This time, Voice Changer should appear in the Effect menu.
6) You are ready to process your audio!