GitHub Advanced Security trials now available for more GitHub Enterprise customers
Source: GitHub Changelog

Trial Availability
More GitHub Enterprise customers can now start a self‑serve GitHub Advanced Security trial to evaluate GitHub Code Security and GitHub Secret Protection. Enterprises that have previously completed a GitHub Advanced Security trial and did not purchase Advanced Security are now eligible for another trial after 180 days.
To set up a GitHub Advanced Security trial, visit the Enterprise “Billing and licensing” page. Learn more about self‑serve GitHub Advanced Security trials.