Update error

[Router]

Any idea on this error please.

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

Ign:1 http://ppa.launchpad.net/george-edison55...dev/ubuntu focal InRelease
Hit:2 http://archive.canonical.com/ubuntu focal InRelease
Hit:3 http://security.ubuntu.com/ubuntu focal-security InRelease
Err:4 http://ppa.launchpad.net/george-edison55...dev/ubuntu focal Release
  404  Not Found [IP: 91.189.95.85 80]
Hit:5 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:6 http://repo.linuxliteos.com/linuxlite emerald InRelease
Hit:7 http://us.archive.ubuntu.com/ubuntu focal InRelease
Hit:8 http://us.archive.ubuntu.com/ubuntu focal-updates InRelease
Hit:9 http://us.archive.ubuntu.com/ubuntu focal-backports InRelease
Reading package lists...
E: The repository 'http://ppa.launchpad.net/george-edison55/nitroshare-dev/ubuntu focal Release' does not have a Release file.