Error: 'universe' invalid

[nevil]

I don’t have a domain yet. I’m trying to install certbot, following the official docs here (Apache on Ubuntu 18.04).

I’m stuck at this point

$ sudo add-apt-repository universe

Gives me:

Error: 'universe' invalid

Not sure how to continue?

[Osiris]

What’s the contents of the file /etc/apt/sources.list and in any file with the suffix .list under the directory /etc/apt/sources.list.d/?

[nevil]

Below the contents of /etc/apt/sources.list

# deb http://snapshot.debian.org/archive/debian/20190910T000000Z buster main
deb http://deb.debian.org/debian buster main
# deb http://snapshot.debian.org/archive/debian-security/20190910T000000Z buster/updates main
deb http://security.debian.org/debian-security buster/updates main
# deb http://snapshot.debian.org/archive/debian/20190910T000000Z buster-updates main
deb http://deb.debian.org/debian buster-updates main

/etc/apt/sources.list.d folder is empty.

[_az]

That doesn’t look like an Ubuntu server to me - it looks like Debian Buster, in which case you can just install certbot from apt.

What does this say:

cat /etc/os-release