for outbound you will be calling the https://docs.vapi.ai/api-reference/calls/create-call Vapi API endpoint. You can try submitting POST requests to this from the webhook module in GHL, and the submit HTTP request module in Make.com to help you learn how they work. For scheduling appointments you'll want to attach tools to your Vapi agent. You'll also want to receive and process the end-of-call-report somewhere.