It's four years old so the page HTML structure must have likely changed. I'll take a look at it when I'm free and update the script. Thanks for your PR, I'll review and merge the two open PRs as well.
Btw, good work on your JS solution. It's great that it just works without requiring any download or installation. :)
Edit: I see from the other PR it's called `upvoted`.
Edit 2: I changed it to `upvoted` and now I get a 200 OK, but the code crashed right afterwards on `tree.cssselect()`.