apt-key

Key management utility for the APT Package Manager on Debian and Ubuntu. Note: apt-key is now deprecated (except for the use of apt-key del in maintainer scripts). More information: https://manpages.debian.org/latest/apt/apt-key.8.html.

apt-key list

apt-key add public_key_file.asc

apt-key del key_id

wget -qO - https://host.tld/filename.key | apt-key add -

apt-key adv --keyserver pgp.mit.edu --recv KEYID