Documentation page introducing CSS paint() feature not working

[a-figerou]

MDN URL

https://developer.mozilla.org/en-US/docs/Web/CSS/image/paint

What specific section or headline is this issue about?

Play https://developer.mozilla.org/en-US/play

What information was incorrect, unhelpful, or incomplete?

The page is presenting an CSS animation called play() and in order to see it in action, the user click on the button PLAY. It opens in new tab https://developer.mozilla.org/en-US/play.

What did you expect to see?

We should be able to see the text getting colorful. Or at least warn the user it is not a working feature for Firefox according to:
https://developer.mozilla.org/en-US/docs/Web/API/PaintWorkletGlobalScope

Do you have any supporting links, references, or citations?

The console of https://developer.mozilla.org/en-US/play, display on the page, is indicating:
TypeError: CSS.paintWorklet is undefined

Do you have anything more you want to share?

Environment:
Firefox

[a-figerou]

For Chrome:
It just runs indefinitely.

[caugner]

FWIW The browser compatibility table on the page indicates that Firefox does not support paint().