There's always a backports repository for the stable release in Debian: deb http://deb.debian.org/debian buster-backports main contrib non-free deb-src

There's always a backports repository for the stable release in Debian: deb http://deb.debian.org/debian buster-backports main contrib non-free deb-src http://deb.debian.org/debian buster-backports main contrib non-free