E: The repository 'http://archive.ubuntu.com/ubuntu eoan Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. code example

sudo sed -i -re 's/([a-z]{2}\.)?archive.ubuntu.com|security.ubuntu.com/old-releases.ubuntu.com/g' /etc/apt/sources.list