In my Retell setup, the book_appointment tool requires an event type ID. Right now, Iโve only added one (for a 15-minute slot). However, for the business Iโm building this for, the appointment duration depends on the specific service being requested (for example, a bathroom remodel might take 2 hours, while a basic repair might take 30 minutes). Whatโs the best way to handle this so that the AI can book appointments with different durations or event types depending on the service type?