1. Add repository
To add this repository to your system type the following commands as
root:
cat <<EOF > /etc/apt/sources.list.d/ltec-public.list
deb [signed-by=/etc/apt/trusted.gpg.d/ltec-ag.gpg] https://pkg.ltec.ch/public/ $(lsb_release -sc | tr -d "\n") main
EOF
Or you can use your GUI to extend your software sources by adding:
deb https:/pkg.ltec.ch/private/ bullseye main
Make sure to use appropriate codename of your release here!
2. Add GnuPG key
To add our GnuPG key to your keychain execute the followning comand as root:
curl https://pkg.ltec.ch/public/conf/ltec-ag.gpg.key | gpg --dearmor > /etc/apt/trusted.gpg.d/ltec-ag.gpg
3. Update
To update the package list type the following command as root:
apt update