You need to manually approve customers and do not want customers to be booking time with you willy-nilly.
You do so with our 'appointment approval' addon which comes with our Upstart and Power plans.
Simply head into the service you would like to approve before appointments are made > click on service > scroll to the bottom > toggle 'Bookings require approval'
Now when bookings are made you receive an email with a link to approve the appointment first. Then invites are sent.
Video tutorial below: