How to solve focal Release' does not have a Release file?

I am unable to run the apt-get update. Every time I run this command I am getting this error massge. Can someone please help

kgo@ws-kgo:~/Documents/side$ sudo apt-get update
Ign:1 http://dl.google.com/linux/chrome-remote-desktop/deb stable InRelease
Hit:2 http://lenovo.archive.canonical.com focal InRelease                                                               
Hit:3 https://deb.nodesource.com/node_14.x focal InRelease                                                              
Hit:4 http://dl.google.com/linux/chrome/deb stable InRelease                                                            
Hit:5 https://mirror.netcologne.de/ubuntu focal InRelease                                                           
Hit:6 https://mirror.netcologne.de/ubuntu focal-security InRelease                            
Hit:7 https://mirror.netcologne.de/ubuntu focal-updates InRelease                                                  
Hit:8 http://dl.google.com/linux/chrome-remote-desktop/deb stable Release                                          
Hit:9 https://mirror.netcologne.de/ubuntu focal-backports InRelease                          
Ign:10 http://old-releases.ubuntu.com/ubuntu focal InRelease                                 
Ign:11 http://old-releases.ubuntu.com/ubuntu focal-security InRelease  
Err:13 http://old-releases.ubuntu.com/ubuntu focal Release             
  404  Not Found [IP: 91.189.88.247 80]
Err:15 http://old-releases.ubuntu.com/ubuntu focal-security Release
  404  Not Found [IP: 91.189.88.247 80]
Hit:14 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease
Reading package lists... Done
E: The repository 'http://old-releases.ubuntu.com/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.
E: The repository 'http://old-releases.ubuntu.com/ubuntu focal-security 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.

Solution 1:

Ubuntu 20.04 LTS is a supported release; so why would it be found in old-releases as per your post?

Only unsupported or EOL releases are found there and whomever moved it there is many years too early.

Ubuntu 20.04 LTS has standard support until 2025-April, and ESM support for a further 5 years before it reaches EOL and gets moved to old-releases.ubuntu.com (which will occur sometime after 2030-April)

Someone with sudo rights has changed it incorrectly on your machine; reverse that change (ie. those lines should be http://archive.ubuntu.com/ and not http://old-releases.ubuntu.com/)