First, click the + “add other calendars” button, under the Other calendars header in the left sidebar.
Then, ‘subscribe to calendar’. Enter the address to the calendar: errblb91r5rdodi645vq8fjp34@group.calendar.google.com.
You can opt-in to receive email notifications whenever an event is added to our calendar too, by navigating to Calendar settings>Other notifications, and selecting Email notifications for New Events.