1 - From the manager's panel, select Setting & Options > Settings > Other Settings. Under the Email and eTickets section you will see Email listing and the "Email Templates" link is to the right. Click this link.
2 - Select Order Confirmation & eTickets from the pull-down menu:
3 - Choose Insert Tag to add to your email template, such as Store Name and Participant name.
4 - This is how the Receipt will look in the email which is automatically sent:
To learn more about Updating other Email Templates, see How to Update Email Templates
For a list of all Email Templates, see article: Email Templates