customizable config.php question

Since I run Filerun behind an nginx reverse proxy I found the following via a Google search

customizable / config.php

<?php

$config['url']['root'] = 'https://www.example.com/abc'

BUT

This is not on the Advanced Configuration page

https://docs.filerun.com/advanced_configuration

Question

Is this config entry still valid. as it does not seem to be doing anything