https://wiki.debian.org/SourcesList

deb http://deb.debian.org/debian buster main contrib non-free
deb-src http://deb.debian.org/debian buster main contrib non-free

deb http://deb.debian.org/debian-security/ buster/updates main contrib non-free
deb-src http://deb.debian.org/debian-security/ buster/updates main contrib non-free

deb http://deb.debian.org/debian buster-updates main contrib non-free
deb-src http://deb.debian.org/debian buster-updates main contrib non-free