“trusted_domains” pada config/config.php nextcloud

What location/directory is the config.php located in? when I do a locate, I get several config.php files and locations. The documentation just says config/config.php, but does not provide any more on which directory specifically. I am new to server setup for linux. I mostly use Linux as a gui, but am trying to learn more linux command line. I have ubuntu server setup.

/snap/nextcloud/16402/htdocs/config/config.php
var/snap/nextcloud/16402/nextcloud/config/config.php

config.php is located in nextcloud/config/config.php. If you installed nextcloud in /var/www, then the full path would be /var/www/nextcloud/config/config.php
During first setup in that directory you’ll only see config.sample.php which you should copy and paste as config.php and work from there.