Google Calender Integrated with Voiceflow and Make. Need Help!

I’m building an AI agent that can directly book appointments into Google Calendar. The agent also needs to fetch and display available time slots while excluding any already booked times, ensuring no double bookings. I’m using Voiceflow for the conversational flow and Make.com for the backend automation.

Has anyone implemented something similar or can guide me on the best way to handle time slot generation and filtering in Make?