Template:Project-APT-Repository-Add Easy
1. Download the Signing Key.
wget https://www.whonix.org/patrick.asc
2. Optional: Check the Signing Key for better security.
3. Add Whonix's signing key.
sudo apt-key --keyring /etc/apt/trusted.gpg.d/whonix.gpg add ~/patrick.asc
4. Add Whonix's APT repository.
echo "deb https://deb.whonix.org buster main contrib non-free" | sudo tee /etc/apt/sources.list.d/whonix.list