How to change from Business to Personal?

Hello,

So I got Teamviewer on my Phone, Laptop, Desktop.

I use it at work (using my Laptop/Phone) to control my Desktop PC at home.

It was working fine, I don't know what happened and now it says "Trial version expired".

I think maybe because I am using it on my Laptop (at work), and where I work they have Business Internet (I don't know what it called).

Is Teamviewer free for Personal use?

Is there a way to fix my problem?

Thank you