Hello LE THI BE HA,

By default, the email notifications are sent to the customer and employee. They receive the notifications based on the notification template and appointment status. If your email is not added as the employee email, then you can add your email in Notification settings. There is a field named "Send all notifications to additional addresses:". By adding your email here, you will receive all the notification regarding the booking. 

The SMS messages works similarly to this, which means that the SMS messages are sent to both customers and employees by default. But, you can also add the phone number in this field 

Send all SMS messages to additional numbers:

I hope it helps.