Currently the step debugging documentation says:

Browser Application #

The recommended way to initiate a debugging session is by configuring your IDE to accept
incoming debugging connections, and then use a browser extension which sets the right trigger cookie.
Browser Extension Initiation

The extensions are:

Xdebug Helper for Firefox (source).
Xdebug Helper for Chrome (source).
XDebugToggle for Safari (source).

Each extension adds an icon to your browser where you can select which functionality
you want to trigger. Xdebug will continue to start debugging for every request as long
as the debug toggle has been enabled.

This is insufficiently informative. I want to possess the knowledge that will enable me to sculpt the triggering cookie by hand and manually add it to a Postman request. I don't want to need to use a browser extension to first generate a profiling request from the browser, capture it in devtols, and only then learn in this roundabout way how the cookie(s) should be formed. I would like this to be explicitly documented.