server { 
 listen 80;
        root /var/www/html;
        index index.html index.htm index.nginx-debian.html;

          location / {
    if ( $uri = '/index.html' ) {
      add_header Cache-Control no-store always;
    }
    try_files $uri $uri/ /index.html;
  }

# Do not cache sw.js, required for offline-first updates.
  location /sw.js {
      add_header Cache-Control "no-cache";
      proxy_cache_bypass $http_pragma;
      proxy_cache_revalidate on;
      expires off;
      access_log off;
  }
 
 location /api {
   proxy_set_header X-Real-IP $remote_addr;
   proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
   proxy_set_header X-NginX-Proxy true;
   proxy_pass http://127.0.0.1:507;
   proxy_set_header Host $http_host;
   proxy_cache_bypass $http_upgrade;
   proxy_redirect off;
 }
}