On the Red Hat Quay documentation page:
imageContentSources: - mirrors: - bastion.nuc.lab/quayadmin/openshift4 source: quay.io/openshift-release-dev/ocp-release - mirrors: - bastion.nuc.lab/quayadmin/openshift4 source: quay.io/openshift-release-dev/ocp-v4.0-art-dev

Prerequisites

• You have configured a superuser in your config.yaml file. For more information, see Configuring a Red Hat Quay superuser.

The "Configuring a Red Hat Quay superuser" link is broken
https://access.redhat.com/documentation/en-us/red_hat_quay/3/html-single/deploy_red_hat_quay_for_proof-of-concept_non-production_purposes/index?extIdCarryOver=true&sc_cid=7013a00000315UTAAY#red_hat_quay_superuser