It shouldn’t be because you’re not actually the owner of the IP address. If any user could get a cert, they could impersonate any other.
They’re ‘shortlived’ 7 day certs, verified using a HTTP challenge. It doesn’t matter who owns the IP, it’s just a matter of who holds the IP.
I just used a bot to read it: https://web.archive.org/web/20250901133211/https://cheapskatesguide.org/articles/debian-netinstall-waf.html