How to get plugins from github?

As @Birthe says, the developer hasn’t made a “release” which is a built in function of GitHub that allows a finished version to be downloaded.

So, you’re looking at source code in that repo for now, which is only useful for active development and using with NodeJS.

Saq wrote a bit about using GitHub Actions for building an entire TW:

Something similar could be used to automatically build releases for plugins on GitHub.

I’ll put it on my TODO list of documenting.

Hope that helps at least explain some background.