- Your
/etc/apt/sources.list
should look like something like this:
deb http://ftp.us.debian.org/debian [bullseye, bookworm, etc] main contrib non-free
deb http://ftp.us.debian.org/debian [bullseye, bookworm, etc]-updates main contrib non-free
# security updates
deb http://security.debian.org [bullseye, bookworm, etc]-security main contrib