LibreOffice doesn't recognize the font on another laptop?

As mentioned above, it's about LibreOffice. I'm currently in the process of making learning notes and have started working on one laptop. Since I use another smaller (tablet) laptop on the way, I wanted to continue the learning sheet there. The problem, the small laptop doesn't recognize some fonts from the big one. The latest version (6.3) is installed on both of them, although the little one was only updated today. Apparently the font wouldn't exist, it would be replaced now and a lot has been moved. With the big one, however, everything is fine and the writing exists. I've tried reinstalling, but the problem still arises… What could be the problem? Or how can I get it as "accurate" as possible so that everything is not moved on the big laptop again?

Fonts are not part of the Office program. Fonts are part of the operating system. And if some fonts are not displayed on a device, you have to install them.

Now asked stupidly how do you do that? I know little about it

I found out, thanks a lot!