The booking window works from any page that can hold one line of code, so a practice profile, a landing page or a page your marketing agency runs is enough. It is an iframe, which means no plugin and no access to your hosting.
If there is no page at all, the widget has its own address that you can put in an email signature, a message to patients or a business listing. That is usually the fastest way to start taking bookings, and you can move the widget onto a real website later without changing anything on our side.
What you configure once: the services you take bookings for, which specialists appear, the business days and the length of each slot. From then on the calendar is the only place the schedule lives, whether the booking came from the widget or from the phone.