user eneas;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
        worker_connections 768;
        # multi_accept on;
}

        http {

            ##
            # Basic Settings
            ##

            sendfile on;
            tcp_nopush on;
            tcp_nodelay on;
            keepalive_timeout 65;
            types_hash_max_size 2048;
            # server_tokens off;

            # server_names_hash_bucket_size 64;
            # server_name_in_redirect off;

            include /etc/nginx/mime.types;
            default_type application/octet-stream;

            ##
            # SSL Settings
            ##

            ssl_protocols  TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
            ssl_prefer_server_ciphers on;

            ##
            # Logging Settings
            ##

            access_log /var/log/nginx/access.log;
            error_log /var/log/nginx/error.log;

            ##
            # Gzip Settings
            ##

      gzip on;
            gzip_disable "msie6";


            include /etc/nginx/conf.d/*.conf;
            include /etc/nginx/sites-enabled/*;
    }

server {
    listen 80;
    listen 443 ssl;
    server_name eneas;

    ssl_certificate /etc/nginx/ssl/.../ssl-bundle.crt;
    ssl_certificate_key /etc/nginx/ssl/.../SSL_PrivateKEY....._$

    location / {
    proxy_pass https://www.example.com:3000;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection 'upgrade';
    proxy_set_header Host $host;
    proxy_cache_bypass $http_upgrade;
    }
}

new version
    var server = app.listen(app.get('port'), console.log('Express server listening on port'+app.get('port'))); // port is 3000

old version
var server = https.createServer(options,app).listen( app.get('port'),function(){
    console.log('Express server listening on port'+app.get('port'));
});

// I change it based on https://stackoverflow.com/questions/42761992/configuring-https-for-express-and-nginx