Add Real-Time Booking Updates

Website is made on Word Press using Elementor.

I need the Booking Confirmation page on my WordPress site to do more than just show a static message. The goal is to display real-time availability status changes the moment a visitor completes a reservation. All availability information comes directly from Calendly, which also handles the payment step, so the page must listen for Calendly’s webhooks (or an equivalent API) and refresh the status instantly—no manual page reloads.

Current setup:
• WordPress with a standard confirmation template
• Calendly handling time-slot selection and payments
Mini Orange application for Mobile OTP confirmation needs to be integrated.

What I’m looking for now is a lightweight script or plug-in logic that:
1. Receives the Calendly availability webhook after a successful payment.
2. Updates the confirmation page live—showing the newly blocked time slot, or any remaining slots—without requiring the guest to refresh.
3. Keeps the UX consistent with the existing design and loads quickly on both desktop and mobile.

Acceptance criteria
• After a test booking and payment, the confirmation page must visually reflect the new availability within two seconds.
• No WordPress core files may be altered; the solution must be theme- or plug-in-based.
• Code should be clean, documented, and ready for hand-off so my in-house admin can maintain it.

If you’ve integrated Calendly webhooks or similar real-time APIs into WordPress before, I’d love to see a brief example when you submit.