I have a Calendly Premium account and am using my personal access token to build a customized booking flow.

So far, I’ve successfully integrated the external API to:

Retrieve and display availability

Create a customized calendar UI on my website

The issue is that although availability shows correctly, I cannot complete the booking process through the API.

I’ve reviewed the API documentation, but I’m not sure if I’m missing an endpoint, permission, or specific payload structure required for confirming the booking.

Could someone guide me on:

1. The correct API flow for completing a booking after retrieving availability.

2. Any special parameters or authentication steps needed for booking confirmation.

3. Whether this is possible with only a personal access token or if I need an OAuth setup.