Appointments come from recurring time windows. On the Inquiry Settings page (Manage slots) click + Add window and enter: weekday, From and To, slot duration in minutes (at least 10), an optional break between appointments, and Valid from/to. Tick Enabled and save.

The window appears under Configured windows and can be edited, disabled or deleted. Each active window produces free slots that interested parties see after picking a date.

Full guide in the documentation: Real Estate CRM.