.htaccess for Apache root directory location on ReadyNAS OS 6.10?

I am running Nextcloud on ReadyNAS OS 6.10.  One of the setup guides for Nextlcoud notes I need to make a change to the .htaccess file in the root folder of my web server (not the Nextcloud directory, but the root of the site itself).

I can't seem to locate which directory is the web root - I checked /etc/frontview and /etc/apache2 and several others, and can find the Apache configs, but not the actual folder holding the documents.  Any tips where I can find it?