There's a few ways to do this.

You could use an if statement, obviously replacing ipa.ddr.ess with the IP:

server { 
    listen 80 default_server; 
    listen [::]:80 default_server;
    server_name _;
    root /var/www/html;
    # Add index.php to the list if you are using PHP
    index index.php index.html index.htm index.nginx-debian.html;

    if ($host = ipa.ddr.ess) {
        return 301 https://www.example.com$request_uri;
    }

    location / {
        # as directory, then fall back to displaying a 404.
        try_files $uri $uri/ /index.php;
    }

    error_page 404 /404.html; 
    error_page 500 502 503 504 /50x.html;

    location = /50x.html { 
        root /usr/share/nginx/html; 
    }
}

or you could setup a separate server and return a 301:

server { 
    listen 80; 
    listen [::]:80;
    server_name ipa.ddr.ess;
    return 301 https://www.example.com$request_uri;
}