How I can get username and password When Redirect ?

Hello, I want get username When Web Proxy redirect To url example http://10.0.0.1/page.php
page.php

<?php ... echo ???; ?>

mikrotik does not have php

i known but how i can get username from html or any thing when redirect by web proxy ?

any help please ?

Add to web-proxy http://domain.com/mikrotik.php?login=anything

/ip proxy access
add action=deny redirect-to=domain.com/mikrotik.php?login=anything