Launchpad GPG Keys error preventing OS updates

I’ve installed the Launchpad repository on my Librem 14 and am getting an error about missing GPG keys. I’ve searched and tried some things but it hasn’t worked yet.

When I click the Download button in the software center Updates section, I get the following error message. It looks like there should be more info, but it almost appears that the message box is cut off and I can’t scroll down to see any more info.

“Unable to Download Updates: The following packages have unmet dependnecies”

This is what I got from someone: “Well, you have a problem with that ubuntu repo (http://ppa.launchpad.net/yktooo/ppa/ubuntu), you either need to remove it or add its GPG keys.”

When I run sudo apt update in Terminal this is what I get:

bsmith@PapasDragon:~$ sudo apt update
[sudo] password for bsmith:
Hit:1 https://brave-browser-apt-release.s3.brave.com stable InRelease
Hit:2 http://repo.pureos.net/pureos byzantium InRelease
Hit:3 http://download.opensuse.org/repositories/home:/manuelschneid3r/Debian_10 InRelease
Hit:4 http://repo.pureos.net/pureos byzantium-security InRelease
Get:5 http://ppa.launchpad.net/yktooo/ppa/ubuntu impish InRelease [17.5 kB]
Hit:6 http://repo.pureos.net/pureos byzantium-updates InRelease
Hit:7 https://repo.protonvpn.com/debian stable InRelease
Err:5 http://ppa.launchpad.net/yktooo/ppa/ubuntu impish InRelease
The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 66EFE2D582CE5D8A
Reading package lists… Done
W: GPG error: http://ppa.launchpad.net/yktooo/ppa/ubuntu impish InRelease: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 66EFE2D582CE5D8A
E: The repository ‘http://ppa.launchpad.net/yktooo/ppa/ubuntu impish InRelease’ is not signed.
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.
bsmith@PapasDragon:~$

I greatly appreciate any support anyone can offer.

Here is what I tried that did not work:

“Launchpad-getkeys” is a script that imports these missing keys automatically. Follow below steps to get free from this hassle.

sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install launchpad-getkeys
After installing, to import just run:

sudo launchpad-getkeys

Below is the output when I tried to run these commands:
bsmith@PapasDragon:~$ sudo apt-add-repository ppa:nilarimogard/webupd8
[sudo] password for bsmith:
The main Web Upd8 PPA maintained by: http://www.webupd8.org/

To add this PPA, simply paste this in a terminal:
sudo add-apt-repository ppa:nilarimogard/webupd8

Packages in this PPA: audacious, ap-hotspot, awn-applet-radio, awn-applet-wm, calise, cmus, dockbarx, dockbarx-themes-extra, dropbox-share, emerald, exaile, fbmessenger, gnome-subtitles, gnome-window-applets, grsync, grive, gthumb, launchpad-getkeys, mc, mdm (Mint Display Manager), minitunes, minitube, musique, notifyosdconfig, nautilus-columns, powertop, ppa-purge, rosa-media-player, fixed pulseaudio-equalizer, subtitleeditor, syncwall, umplayer, unity-reboot, wimlib, youtube-dl, xfce4-dockbarx-plugin, xournal, yad, yarock and others. Almost all packages are updated to their latest version.

For other (specialized) PPAs we maintain, see: https://launchpad.net/~webupd8team
More info: https://launchpad.net/~nilarimogard/+archive/ubuntu/webupd8
Press [ENTER] to continue or ctrl-c to cancel adding it

gpg: keybox ‘/tmp/tmp810be83y/pubring.gpg’ created
gpg: /tmp/tmp810be83y/trustdb.gpg: trustdb created
gpg: key 531EE72F4C9D234C: public key “Launchpad webupd8” imported
gpg: Total number processed: 1
gpg: imported: 1
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
gpg: no valid OpenPGP data found.
bsmith@PapasDragon:~$ sudo apt-get update
Ign:1 http://ppa.launchpad.net/nilarimogard/webupd8/ubuntu jammy InRelease
Hit:2 http://deb.anydesk.com all InRelease
Err:2 http://deb.anydesk.com all InRelease
The following signatures were invalid: EXPKEYSIG 18DF3741CDFFDE29 philandro Software GmbH info@philandro.com
Hit:3 https://brave-browser-apt-release.s3.brave.com stable InRelease
Hit:4 https://linux.teamviewer.com/deb stable InRelease
Get:5 http://repo.pureos.net/pureos byzantium InRelease [5,851 B]
Hit:6 http://ppa.launchpad.net/yktooo/ppa/ubuntu impish InRelease
Hit:7 http://download.opensuse.org/repositories/home:/manuelschneid3r/Debian_10 InRelease
Hit:8 https://repo.protonvpn.com/debian stable InRelease
Get:9 http://repo.pureos.net/pureos byzantium-security InRelease [4,581 B]
Err:10 http://ppa.launchpad.net/nilarimogard/webupd8/ubuntu jammy Release
404 Not Found [IP: 91.189.95.85 80]
Get:11 http://repo.pureos.net/pureos byzantium-updates InRelease [4,580 B]
Reading package lists… Done
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://deb.anydesk.com all InRelease: The following signatures were invalid: EXPKEYSIG 18DF3741CDFFDE29 philandro Software GmbH info@philandro.com
E: The repository ‘http://ppa.launchpad.net/nilarimogard/webupd8/ubuntu jammy 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.
bsmith@PapasDragon:~$ sudo apt-get install launchpad-getkeys
Reading package lists… Done
Building dependency tree… Done
Reading state information… Done
E: Unable to locate package launchpad-getkeys