This setting simplifies communication with your clients during the appointment booking process. You can choose how to interact with them via email and SMS, and for what purposes, such as sending notifications about bookings, cancellations, reminders, or changes. 

You can select from pre-designed templates or customize them according to your needs. This ensures that your email and SMS messages are tailored to your specific requirements and enhance your client interactions.

In reference to the settings shown in the above images, these options are for managing email & SMS templates and enabling or disabling notifications for specific purposes, such as sending sms / emails during bookings, cancellations, appointment changes, etc.