# mkdir -m 0755 -p /etc/apt/keyrings
# curl -fsSL http://http://packages.its-treason.com/ui/pgp | gpg --dearmor -o /etc/apt/keyrings/packages_its-treason.gpgReplace CODENAME COMPONENT with values from list of all suites
# echo \
"deb [arch="$(dpkg --print-architecture)" signed-by=/etc/apt/keyrings/packages_its-treason.gpg] \
http://packages.its-treason.com CODENAME COMPONENT" |
tee /etc/apt/sources.list.d/packages_its-treason.list > /dev/null
# apt update