How to implement cool ashes effect in blocs

I am trying to make cool ashes effect on my blocs page.
Нere https://pcvector.net/codepen/646-jeffekt-letjaschego-pepla.html I can get html, js and css code but when I just embed it in Code Widget (using for js code and for css) I get nothing.

Can somebody tell me the way of proper realisation of this html and js code?

Thanks a lot