GCal Events List retrieves events from Google Calendar and shows data in a widget.
To make GCal Events List work properly, you have to activate the plugin and paste your Google Calendar API key and a public calendar ID in the widget admin panel.
It requires some other options. Here is the full list of params:
For a detailed description of calendar settings, read the Google Calendar Data API documentation
REMEMBER: your Google Calendar must be public, otherwise the widget won’t show any event!