Installing Mesact

cnc@raspberrypi:~$ sudo apt update Hit:1 http://deb.debian.org/debian bookworm InRelease Hit:2 http://deb.debian.org/debian bookworm-updates InRelease Hit:3 http://download.opensuse.org/repositories/science:/EtherLab/Debian_12 ./ InRelease Hit:4 http://deb.debian.org/debian bookworm-proposed-updates InRelease Hit:5 http://deb.debian.org/debian-security bookworm-security InRelease Hit:6 http://deb.debian.org/debian bookworm-backports InRelease Hit:7 https://packages.microsoft.com/repos/vscode stable InRelease Hit:8 https://www.linuxcnc.org bookworm InRelease Get:9 https://gnipsel.com/mesact/apt-repo stable InRelease [2,608 B] Err:9 https://gnipsel.com/mesact/apt-repo stable InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6F8DFB65A82CD322 Reading package lists... Done W: GPG error: https://gnipsel.com/mesact/apt-repo stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6F8DFB65A82CD322 E: The repository 'https://gnipsel.com/mesact/apt-repo stable 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.