How the Book a Demo page on versusnetworks.com books into the calendar the Versus platform operator manages under Versus Support → Demo Booking Calendar, and what both sides receive.
Book a Demo on versusnetworks.com lets a prospect describe their environment, pick a time from the slots the Versus team has published, and receive a calendar invite. The slots come from Versus Support → Demo Booking Calendar inside Versus, a page only the platform operator (the admin super user) can open.

.ics and a Google Calendar link. The confirmation email carries a real calendar invite (Accept / Decline in Outlook, Gmail and Apple Mail) and a cancel link.

Every booking emails the visitor a confirmation and the operator a notification, both with the invite attached as text/calendar (METHOD:REQUEST) and as invite.ics, so the demo lands on both calendars. A cancellation from either side sends METHOD:CANCEL, which removes it again. Mail goes through the SMTP settings under Settings → Email (SMTP); without SMTP configured nothing is sent, but bookings are still recorded.
The calendar carries whatever join link you give it. Microsoft Teams is the natural fit for a Versus team already integrated with Teams: a standing meeting link from Teams, or a per-booking meeting created through Microsoft Graph, works with the invite as is. Google Meet and Zoom links work the same way.
The site talks to Versus server-to-server. The public endpoints only list open slots and accept a single booking or a token-based cancellation; they are throttled per IP, refuse bots through a hidden form field, and, when DEMO_BOOKING_KEY is set on both sides, accept calls only from the site. Everything else on the calendar requires the platform operator.