Calendar Syncing Problem. Follow-up to first questions responded to by Jack Kitterhing

HOW DO YOU ATTACH TO ORIGINAL THREAD? Tried email but rejected and cannot therefore send attachment.
Hi Jack,
Thanks for prompt reply. No problem in overlaying all appointments and appointments from new calendar are OK and as per final test. My problem is that if client chooses from the website, in our case, say Dr. Dominic Bostock, as the service provider, because there is no sync between the calendars, the client can be offered time slots that are already taken.
I am assuming that Appointment+ can be added to our existing manual Google Calendar system and that the existing calendar can be sync'd to the new calendar that I have created within Appointment+ but I may have misunderstood how the system works, hence my question, do I need to transfer all appointments in the old/existing Google Calendar, delete calendar and transfer to the new Appointment+ calendar? I have also tried to make the old calendar, the selected calendar by using its calendar ID in the set up but this does not work and the front end page does not show any of the current bookings?

On the second point of Service Providers (which may be part of the above problem).......we have two Doctors, Dr Dominic Bostock (my son) and Dr Sharon Coenen, each added to the APP+ set up. Each would have their own calendar, I presume, in order for clients to choose and be able to book their slot. However, I can't create anything in the user profiles for each of them as the data entry points are greyed out and inactive. I've tried everything I can think of to overcome this but with no luck.

I've attached a screen shot but not sure which GCal page you are referring to.

Hope this makes sense as I am a bit confused. All the vids on other set up areas are great, its just the Google Cal syncing which I can't get my head around.