Room feature is used in the calendar section from where you can book manual appointments and assign different rooms for particular services.
Here are the steps to add different room:
1. Go to Setup >> Calender settings >> under appointment settings >> enable the room feature and click on SAVE.
Click on Rooms >> Click on ( + ) button to add different rooms
Add Room Name, Click Save.
Now, Go to Calendar >> Room Calendar
1. Click on active part to book an appointment, A pop up will appear from where you can fill in the customers details,
2. Select service and assign a Room for a particular service.
Note: If a room is booked for a particular time slot, then the same room cannot be booked for the same time slot for a different customer.
Also, Here is the tutorial video for your reference: