If not selected already, select the Availability Google Calendar in Settings > Google Calendar - this is the calendar from which the availability events are read.
The Availability calendar can coincide with the Linked Google Calendar, yet the plugin permits to separate them, so you can hide the availability calendar in your main Google Calendar view, for visual clarity.
How to create availability events
To add an availability interval, create a new event in the Availability Google Calendar. The title of the event determines what service the availability interval is intended for:
If the title of the event is equal to the service name, the event is considered as an availability interval for that service.
If the title of the event is the word all then the event is considered as an availability interval for each active service - it is "replicated" for any service.
An availability interval may be splitted into time slots or considered as a whole timeslot, according to the service Duration and availability settings.
Can I create recurring availability events?
Yes, you can create single events and recurring events as well.