sudo nano /etc/apt/sources.list
deb http://deb.debian.org/debian bullseye-backports main contrib non-free deb-src http://deb.debian.org/debian bullseye-backports main contrib non-free
sudo nano /etc/apt/sources.list
deb http://deb.debian.org/debian bullseye-backports main contrib non-free deb-src http://deb.debian.org/debian bullseye-backports main contrib non-free