Как правильно настроить Nginx proxy для content-lenght?

server {
	listen 443 ssl;
        server_name servename;
        ssl_certificate /path/...
        ssl_certificate_key /path/...

        location /api/ {
              proxy_pass http://localhost:3000;
              proxy_buffering off;
              proxy_set_header X-Accel-Buffering: no;
    	      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_cache_bypass $http_upgrade;
	
	}
}