The email notification can be set up on the store administration page.
  1. Select the configuration tab.
  2. Select the email tab under the store configuration.
  3. Enter the email to receive the notification under the 'Send Purchase Notification To' field. 
  4. Add a subject line to the receipt email subject line field.
  5. Update the receipt email body text/html if necessary.
  6. Save.
For more information, refer to our eStore guide