To create a new appointment, click and drag or just click on the empty calendar slot. In the opened window you may choose one of the options
Select Patient - Select a patient from existing records
New Patient - Create new patient record
No patient - Create an appointment without patient, just a simple calendar note
Time Slot - create a section that indicates working hours for providers (dentists)
After you entered room, provider, and patient, you may add additional note, for example treatment that needs to be done.
Click on the Save button to create this appointment