from the Designer FAQ: https://cherryaudio.com/voltage-module-designer/faq
Can my modules be free?
Yes, but we currently have a limit on the number of free modules an individual manufacturer can offer in our Store. That limit is currently 2 free modules.
not only, but there is even a minimum price for paid modules
If I sell my modules, is there is a minimum price I can charge?
Yes. Modules can be sold for any price at or over US$10.
this is a commercial suicide. no wonder why nobody want to buy my license of VM on the sell & buy forum