Tools > DBGp Proxy > Configuration
IDE Key: PHPSTORMHost: 127.0.0.1Port: 9000
Install an Xdebug helper on your browser and set the key to PHPSTORM.
You can now click on Run > Start listening for PHP Debug connection in PhpStorm and enable the browser extension.
Put a debug break point.
Have fun!
After putting a breakpoint in a file that was symlinked you will probably encounter this:
To fix that issue you need to click on "Click to set up path mappings" in order to map the symlink path to the real path like so:

