How to block access using the server IP and redirect non-www to www with SSL in Nginx?

Hello all!

1. I have configured a domain using an Ubuntu 18.04 DO droplet.
2. I have successfully installed Nginx.
3. I have followed and successfully installed SSL using the tutorial here digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-18-04

Q1. How to block access using the server IP and return error 444 on SSL? As you can see in my configuration it blocks at port 80.

Q2. I have redirected non-www to www, is that correct?

The configuration for my webserver is:

server {
        root /var/www/html;
        index index.php index.html index.htm index.nginx-debian.html;
        server_name example.com www.example.com;

        location / {
                try_files $uri $uri/ =404;
        }

        location ~ \.php$ {
                include snippets/fastcgi-php.conf;
                fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
        }

        location ~ /\.(?!well-known) {
                deny all;
                }

    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem; # m$
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem; #$
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

}
server {
    if ($host = www.example.com) {
        return 301 https://www.example.com;
    } # managed by Certbot
	
    if ($host = example.com) {
        return 301 https://www.example.com;
    } # managed by Certbot

    listen 80;
    server_name example.com www.example.com;
    return 444; # managed by Certbot

}

Kindly help me resolve this.

Thanks in advance!