The x dotnet tool [1] is just used for publishing (+ downloading) your directory to a gist (and does things like handling binary files + directories + ignores build folders, etc), but you can manually create the Gist yourself from https://gist.github.com + all the language examples are gists you can access from https://gist.github.com/<gist-id>

But .NET 5 is also a quick & non-invasive install on macOS / Linux / Win https://dotnet.microsoft.com/download/dotnet/5.0

[1] https://docs.servicestack.net/dotnet-tool