How can I use team viewer when the pc that gets steered is on ethernet and the other one isn't?

Devilish_TL07

So I have my own pc with WiFi on the Internet and the pc I want to access is via ethernet connecter to the Internet. When I now start teamviewer on both PCs the pc on ethernet doesn't show up. Is there something I can change to get it working? Also they are both in the same WiFi network.