If you created an account using your Google Reseller management account, you're already set.
In case you need to connect another Google Reseller account or reconnect your current one, follow these steps:
Go to the Configuration page.
Press the Reconnect button for the Google integration.
You'll be redirected to Google for authentication. Sign in, and review the requested access permissions (1) and our terms & conditions and privacy policy (2). Press the Allow button (3) to complete the process.
You will be redirected back to Goolash. A confirmation message will be shown.