## Security headers for Nginx ##
    add_header Strict-Transport-Security "max-age=15768000" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Xss-Protection "1; mode=block" always;
    add_header Referrer-Policy  strict-origin-when-cross-origin;
    add_header Content-Security-Policy  "$GATEWAY_CSP";