Can't find 'Software & Updates'

[chushingura]

Hi, Cannot find PPA listings.  (I tried menu/settings/scroll down. no 'software and updates' in the list. Also tried search 'software', again no  'software and updates' in the list!)  The following is the initial problem. ===========================
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://ie.archive.ubuntu.com/ubuntu focal InRelease
Hit:2 http://www.mirrorservice.org/sites/repo..../linuxlite emerald InRelease
Hit:3 http://ie.archive.ubuntu.com/ubuntu focal-updates InRelease
Get:4 http://ie.archive.ubuntu.com/ubuntu focal-backports InRelease [108 kB]
Get:6 http://ie.archive.ubuntu.com/ubuntu focal-security InRelease [114 kB]
Hit:7 http://archive.canonical.com/ubuntu focal InRelease
Hit:8 https://brave-browser-apt-release.s3.brave.com stable InRelease
Hit:5 https://deb.librewolf.net focal InRelease
Get:9 https://download.opensuse.org/repositori...untu_Focal  InRelease [1,553 B]
Err:9 https://download.opensuse.org/repositori...untu_Focal  InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 02456C79B2FD48BF
Reading package lists...
W: GPG error: https://download.opensuse.org/repositori...untu_Focal  InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 02456C79B2FD48BF
E: The repository 'https://download.opensuse.org/repositori...untu_Focal  InRelease' is not signed.