Finding Fonts

I'm having trouble with fonts. On my laptop I've chosen font Modern No 20 in Ai. But when I save the file to the Creative Cloud folder and open the file on my desktop to keep working, it says "The document uses fonts not available on your computer." I know about adding and syncing fronts through Adobe but I cannot find this font anywhere.

I've been working on the latest versions on both laptop and desktop- the Modern No 20 font is available to be selected on my laptop but not on my desktop.

Any help would be much appreciated! Thank you!