The finale configuration of your nginx config file

nginx_config

#HTTP CONFIG START
server {
  listen 80;

  server_name  domainname.com;

  if ($scheme = 'http') {
          rewrite ^ https://$http_host$request_uri? permanent;
        }
}

server {
    listen              443 ssl;
    server_name         domainname.com;
    ssl_certificate     /etc/letsencrypt/live/domainname.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/domainname.com/privkey.pem;
    
    location / {
        proxy_pass http://localhost:3333;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_cache_bypass $http_upgrade;
    }
}