Intro

As of Debian 11 apt-key should not be used. Instead, it is recommended to use GPG keys. So, here is a quick post that explains how to use GPG keys in verification of apt packages.

Step1 - Create keyfile

KEYRING=/usr/share/keyrings/jcameron-key.gpg
curl https://download.webmin.com/jcameron-key.asc | gpg --dearmor | sudo tee "$KEYRING" > /dev/null 2>&1
echo deb [signed-by="$KEYRING"] https://download.webmin.com/download/repository sarge contrib | sudo tee /etc/apt/sources.list.d/webmin.list

Also Note

Below, is an example of curl for http instead of https notice the -fsSL flag added

curl -fsSL http://www.webmin.com/jcameron-key.asc | gpg --dearmor | sudo tee "$KEYRING" >/dev/null

The Breakdown

This is not to difficult