I want Appointments+ to read my service providers' own google calendars to see when they are available.
To do this I presume I allow service providers google Calendar API integration. Then each user completes the integration information on their user profile.
I don't understand the reference to not using your primary google calendar. That's the whole point of the exercise. Are you saying each service provider has to create a new google calendar? If so that calendar will have no appointments in it whereas the primary calendar has all the information that would make this app useful.
Am I missing something?