Docs feedback: "Disable public access to Pages sites" checkbox missing from where documentation says it should be

The documentation at this link does not match my self-hosted instance of GitLab.
https://docs.gitlab.com/13.8/ee/administration/pages/index.html#disabling-public-access-to-all-pages-websites

I navigated to my instance’s Admin Area > Settings > Preferences and expanded Pages settings. I do not see a "Disable public access to Pages sites" checkbox there.

GitLab version: 13.8.0-ee