If you are using a Third Party Service utilizing the Paytronix Online Ordering's API, you can add their URL as an endpoint to your restaurant easily.
Visit your General Settings page. When on the General Settings page, just add /advanced to your web browser's address bar.
For example:
opendining.net/admin/restaurants/[UNIQUE RESTAURANT ID]/settings/advanced
When on this page, you will see the "Webhook Endpoint" option under Restaurant Settings.