title: Why do I still get "N: See apt-secure(8) manpage for repository creation and user configuration details." weeks after
body: <p>Few weeks ago I tried to install an IDM replica on Ubuntu 20.04 from Focal. However I got an error and from ever since, whenever I run &quot;Sudo apt update&quot; the same error returns.</p>
  <p>Err:17 <a href="http://ppa.launchpad.net/noobslab/apps/ubuntu" rel="nofollow noreferrer">http://ppa.launchpad.net/noobslab/apps/ubuntu</a> focal Release<br />
  404  Not Found [IP: 91.189.95.85 80]
  Reading package lists... Done
  E: The repository 'http://ppa.launchpad.net/noobslab/apps/ubuntu focal Release' does not have a Release file.
  N: Updating from such a repository can't be done securely, and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  <a href="https://i.stack.imgur.com/vfzHN.png" rel="nofollow noreferrer">Screenshot of the terminal</a></p>