Introduction example is broken on https://webtorrent.io/intro

I just pasted the contents of "HTML example with status showing UI" on https://webtorrent.io/intro into a file called sample.html, opened that in my browser, and whilst the video downloads, the video does not play.

Brave 1.65.114 Chromium: 124.0.6367.60 (Official Build) (64-bit)