Integrating SAP Qualtrics with SAP Marketing

Hello Experts,
 I am currently looking at this guide provided by SAP regarding an integration between SAP Marketing and Qualtrics:https://help.sap.com/viewer/d39ca7da7f8e4aa4bf2d1d5dc9930324/1911.500/en-US
I am trying to understand how the Qualtrics system is integrated with the CPI system in terms of registering the third-party survey provider webhook. And also needs to know how to do the coding to call the Publication URL of CPI system, when the event Subscription is created.
I checked this API documentation https://api.qualtrics.com/docs/listen-to-and-retrieve-responses-in-real-time and needs to know where to do the logic in Qualtrics to send the Survey Responses.
Need your valuable inputs on this.
Thanks,
Ezhil.