Error: Failed to download metadata for repo 'appstream' | CentOS 8 EOL

This video covers CentOS 8 EOL status, and provides instructions for fixing the “Error: Failed to download metadata for repo ‘appstream’: Cannot prepare internal mirrorlist: No URLs in mirrorlist” issue when trying to use yum or dnf to update or install packages.

KB – https://kb.confusedit.org/books/centos/page/error-failed-to-download-metadata-for-repo-appstream