This sample illustrates how to sync Scheduler Appointments with Events from Google calendar. To launch run the application you need follow steps 1 to 3b of this article to download the "credentials.json" file and include it into your project.
You will also need to remove all Google assemblies referenced in the project, then go to Project - Manage NuGet Packages... and remove installed packages. To quickly re-install these packages and reference required libraries, drop a new DXGoogleCalendarSync component from the VS Toolbox onto the form and click "Accept" in the appeared dialog. After all packages are successfully installed, you can remove this DXGoogleCalendarSync component.
See the Synchronization With Google Calendars documentation article for instructions.