Chauffeur Booking System Google Calendar sync

Im trying to get my Chauffeur Booking System bookings synced to my Google Calendar but finding it tedious. Normally an API key, 0Auth2 and URI would do the trick but it doesn’t seem as simple with this plugin. Anyone who can share some insight please? Unfortunately I cant receive support from the author since I bought the license from Envato.

I can’t see any buyer badge in your profile (renaldocoetz). You will need to contact the author through your original account (purchased the item).