Error updating please help!

[musicianfree]

Hi:

I am new to Linux Lite and every time I try to update i get this log. Please help. This is the log.

===========================
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 ===========

Get:1 http://security.ubuntu.com/ubuntu focal-security InRelease [114 kB]
Hit:2 http://us.archive.ubuntu.com/ubuntu focal InRelease
Get:3 http://us.archive.ubuntu.com/ubuntu focal-updates InRelease [114 kB]
Get:4 https://repo.skype.com/deb stable InRelease [4,502 B]
Hit:5 http://repo.linuxliteos.com/linuxlite emerald InRelease
Get:6 http://us.archive.ubuntu.com/ubuntu focal-backports InRelease [101 kB]
Hit:7 https://packages.microsoft.com/repos/ms-teams stable InRelease
Err:4 https://repo.skype.com/deb stable InRelease
  The following signatures were invalid: EXPKEYSIG 1F3045A5DF7587C3 Skype Linux Client Repository <[email protected]>
Hit:8 http://dl.google.com/linux/chrome/deb stable InRelease
Ign:9 http://linux.dropbox.com/ubuntu disco InRelease
Hit:10 http://linux.dropbox.com/ubuntu disco Release
Hit:12 http://archive.canonical.com/ubuntu focal InRelease
Reading package lists...
W: GPG error: https://repo.skype.com/deb stable InRelease: The following signatures were invalid: EXPKEYSIG 1F3045A5DF7587C3 Skype Linux Client Repository <[email protected]>
E: The repository 'https://repo.skype.com/deb stable InRelease' is not signed.