Certificate is not issued due to unauthorization for my iredmail server domain

My domain is: sfin.in

I ran this command: certbot certonly --webroot -d mail.sfin.in -w /var/www/html
and my webserver is on nginx. I tried everything but is still gives error

The -w /var/www/html should appear before the -d mail.sfin.in

An Apache server is currently replying to HTTP requests to your mail.sfin.in domain

Request to: mail.sfin.in/, Result: [Address=,Address Type=IPv4,Server=Apache/2.4.6 (CentOS) OpenSSL/1.0.2k-fips PHP/5.6.40


How to close this apche server in my domain so i should host mail server

There are many ways to manage servers. Maybe ask on a forum for server setup in general. We help mostly with the certificates and common server configuration problems.

Or ask your hosting company if you have one.