You will need to use an app such as Touchless for WIndows/Mac to allow you to interact with your computer using the Leap Motion controller and Google Earth pro.
You will need the V2 software from here with the hotfix applied from here if you are using Windows 10.
The application itself can be downloaded from the links below:
Touchless for Windows
Touchless for Mac
Once downloaded and installed I recommend reading the getting started section and help guide to familiarise yourself with how to use this.