To enable login via your Google account you need to enable this option in Settings of the plugin and then enter your Google client key and secret there:
How to get Google client ID and secret. Navigate to Google API Console Credentials page >> https://console.cloud.google.com/ where you need to press Create credentials and select Create OAuth client ID.
Then please do the following:
1. Select Web application.
2. Name it.
3. Add Authorized redirect URIs in the following format: https://yourdomain.com/?auth_network=google
4. Press create and copy your Client ID and your Client Secret and paste into the plugin settings.