wordfence blocked my url hide script

Hi!

I tried to add the code;

<script>       window.history.replaceState('','','/');
</script>

in XYZ php code plugin, because I want one page to “hide” the true url, but wordfence stopped me when i pressed save, but I don’t understand why?

A potentially unsafe operation has been detected in your request to this site

Your access to this service has been limited. (HTTP response code 403)

If you think you have been blocked in error, contact the owner of this site for assistance.

Wordfence