From the Admin UI, select the Settings tab
Select the UI Setup tab
To turn on the online scheduler so parents can use the website and schedule appointments, modify the “Start day of appointment taking” and the “End day of appointment taking.” Any days that you want to make available for parents to schedule appointments should be within the start and end date specified.
To allow yourself (and other Administrators) access to the scheduler when it is closed to your parents, check the box "allow Admins access to the CUI at all times".
At the top of the UI Setup page you will see the URL for the selected event. Each event on an account has a unique event number which can be included in the URL to take the parent directly to that event.
If you only have one event on your account, then you should use the URL for the entire account. This URL is found on the Global Setup / Business Setup page and is listed under the Appointment URL for customer.
Once you have opened up the site you should try it out as if you were a parent.