What to put in jetpack CSS editor to get rid of default wordpress footer?

Can you provide a link to the website with that footer?

absolutely. here’s my webpage: https://www.howtodetailmycar.com/

Try using a browser inspector tool for this kind of CSS work.
I used Google Chrome’s Developer Tool and exposed the HTML <div class="site-info"> https://snag.gy/j27KU.jpg .
This shows you need to add the following in jetpack’s CSS editor;

.site-info {
 display: none;
}

hey awesome! Thanks so much, I do have that developer tool, but I’m still trying to learn how to use it.

Thanks so much!

Resolved ??