nginx config for vhost setup to proxy for an app running at 3000

nginx-vhosts.config

fastcgi_cache_path /var/cache/nginx/welcome.com_fastcgi levels=1:2 keys_zone=welcome.com_fastcgi:5m max_size=67108864;

server {
        listen XXX.XX.XX.XX:80;

        server_name example.com;
        server_name www.example.com;
        server_name ipv4.example.com;

        error_page 400 "/error_docs/bad_request.html";
        error_page 401 "/error_docs/unauthorized.html";
        error_page 403 "/error_docs/forbidden.html";
        error_page 404 "/error_docs/not_found.html";
        error_page 500 "/error_docs/internal_server_error.html";
        error_page 405 "/error_docs/method_not_allowed.html";
        error_page 406 "/error_docs/not_acceptable.html";
        error_page 407 "/error_docs/proxy_authentication_required.html";
        error_page 412 "/error_docs/precondition_failed.html";
        error_page 414 "/error_docs/request_uri_too_long.html";
        error_page 415 "/error_docs/unsupported_media_type.html";
        error_page 501 "/error_docs/not_implemented.html";
        error_page 502 "/error_docs/bad_gateway.html";
        error_page 503 "/error_docs/maintenance.html";

        location ^~ /error_docs {
                root "/var/www/vhosts/example.com";
        }

        client_max_body_size 128m;


        access_log "/var/www/vhosts/system/example.com/logs/proxy_access_log";
        error_log "/var/www/vhosts/system/example.com/logs/proxy_error_log";

        add_header X-Cache-Status $upstream_cache_status;
        set $no_cache "";

        set $cache_cookie $http_cookie;

        if ($cache_cookie !~ "^\s*$") {
                set $no_cache 1;
        }

        location ~ /\.ht {
                deny all;
        }

        location @fallback {
                return 404;
        }

        location / {
                proxy_pass http://127.0.0.1:3000;
                proxy_set_header Host             $host;
                proxy_set_header X-Real-IP        $remote_addr;
                proxy_set_header X-Forwarded-For  $proxy_add_x_forwarded_for;
                proxy_set_header X-Accel-Internal /internal-nginx-static-location;
                access_log off;

        }

        add_header X-Powered-By PleskLin;

}