Oh, this is a common problem with Hostinger. There are both IPv4 and IPv6 addresses in your DNS for that domain name. Hostinger seems to add the IPv6 for new setups but it points to a LiteSpeed server for them.
Let's Encrypt prefers IPv6 when present which is why you see that address in the error message. The "404" means that server told the LE server it could not find the info to reply properly. And, it wouldn't know how because Certbot is running on your nginx server.
Either change your AAAA record to be your server or remove it.