Errors when fetching updates

[anniejca2002]

When trying to fetch updates, I get the following error message:
===========================
Install Updates Error log
===========================
Install Updates could not fetch the package cache information lists.
Go to https://www.freecinema2022.gq/forums/ and paste the log below into a new or existing thread for assistance.

============ Log ===========

Hit:1 http://archive.canonical.com/ubuntu focal InRelease
Hit:2 http://repo.linuxliteos.com/linuxlite emerald InRelease
Hit:3 http://us.archive.ubuntu.com/ubuntu focal InRelease
Hit:4 http://us.archive.ubuntu.com/ubuntu focal-updates InRelease
Ign:5 http://ppa.launchpad.net/dupeguru/ppa/ubuntu focal InRelease
Hit:6 http://security.ubuntu.com/ubuntu focal-security InRelease
Hit:7 http://us.archive.ubuntu.com/ubuntu focal-backports InRelease
Err:8 http://ppa.launchpad.net/dupeguru/ppa/ubuntu focal Release
  404  Not Found [IP: 91.189.95.83 80]
Hit:9 https://repo.skype.com/deb stable InRelease
Reading package lists...
E: The repository 'http://ppa.launchpad.net/dupeguru/ppa/ubuntu focal Release' does not have a Release file.