如何为webserver中内置的phpstorm启用.htaccess支持

I read, that the builtin webserver of phpstorm supports .htaccess (as apache does).
I defined a .htaccess in the root directory

RewriteEngine on
RewriteRule .html index.php

Calling anything.html should load index.html but I get a 404-Error.

I cann´t find a config to switch the .htaccess on.
Any idea what´s going wrong?