Set up SAML SSO with Velo - naming callback assertion

Hi, I’m tryin to set up SAML SSO with Azure using this article:

The first step is to name the callback assertion using the following instructions:

Naming the Assertion Callback Function
This function handles the POST request from the IDP containing the encrypted user credentials. The function is defined in the http-functions.js back end file.Our function needs to handle the post of the Assertion Consumer Service (ACS) URL so let’s call it **post_assertion. ** The ACS is an XML document that contains the user authorization and user credentials.
If our site’s URL is , then the URL of our assertion handler is

First question: These instructions don’t a snippet/suggested format for post_assertion function to add to the http-functions.js file. Can you please help?
Second question: should the URL for the assertion handler point to a specific page that I define, or is the homepage sufficient (e.g. )

Thank you!