pqdoctor APT repository

For Debian, Ubuntu and other apt-based Linux, x86_64 and arm64. Add the repository once:

curl -fsSL https://apt.pqdoctor.com/key.gpg | sudo gpg --dearmor -o /usr/share/keyrings/pqdoctor.gpg
echo "deb [signed-by=/usr/share/keyrings/pqdoctor.gpg] https://apt.pqdoctor.com stable main" | sudo tee /etc/apt/sources.list.d/pqdoctor.list
sudo apt update && sudo apt install pqdoctor

sudo apt upgrade then keeps it up to date. Documentation: pqdoctor.com.