Welcome to nginx - how to get to the site?

Question

Nginx

Everything got up, everything was set up, the necessary services and programs started.
(We put the Postal mail server)
But I can’t log in, it gives the Welcome to nginx stub.
How to get into the system?
nginx config

server {
    listen [::]:80;
    listen 0.0.0.0:80;
    server_name postal.domayn.ru;
    return 301 https://$host$request_uri;
}

server {
    listen [::]:443 ssl;
    listen 0.0.0.0:443 ssl;
    root /opt/postal/app/public;
    server_name postal.domayn.ru;
    ssl_certificate      ssl/postal.cert;
    ssl_certificate_key  ssl/postal.key;

    # Generate using: openssl dhparam 4096 -out /etc/ssl/dhparam.pem
    # ssl_dhparam /etc/ssl/dhparam.pem;

    ssl_protocols TLSv1.2 TLSv1.1 TLSv1;
    ssl_prefer_server_ciphers on;
    ssl_ciphers EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA512:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:ECDH+AESGCM:ECDH+AES256:DH+AESGCM:DH+AES256:RSA+AESGCM:!aNULL:!eNULL:!LOW:!RC4:!3DES:!MD5:!EXP:!PSK:!SRP:!DSS;

    location / {
       client_max_body_size 50M;
       try_files $uri $uri/index.html $uri.html @puma;
    }

    location /assets {
       add_header Cache-Control max-age=3600;
    }

    location @puma {
        proxy_set_header X-Real-IP  $remote_addr;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto https;
        proxy_pass http://127.0.0.1:5000;
    }
}

Answer 1

1. what web muzzle
2. what other demons
3. apache configs
4. 0.0.0.0 - what kind of IP is this?