All extensions are enabled on install, in order to do that you just need to open the extension file using Aseprite - it might be as simple as opening the file if you have your Aseprite installed and not portable, with associated file extensions. If you’re using a portable version of Aseprite you can simply drag the extension file over the Aseprite window to open it this way.
You can reach me via Twitter (@thkasparrr) or by email (kac[dot]wozniak[at]gmail[dot]com) ✌️