I'm currently using GHL for it! I just haven't figured out how to get the appointment actually scheduled on my calendar. Currently it just sends the appointment info like a basic string of text like appointment day - "wednesday" or "april 25" appointment time - "3 pm" Then this string is attached to the GHL contact and we get a notification that the appointment was "booked". Then we manually create the appointment on our calendar etc. Super basic and rudimentary. Kinda works but not ideal at all. Ideally Vapi would book directly on our GHL calendar if possible