How do I enable Server Side Includes on a TeraStation 1200D

[Lauritz]

The issue I'm having may have already been addressed within this forum but I wasn't able to find it.
I've been hosting a small website on my TeraStation 1200D for some time now with no issues; however, I now want to make some changes to simplify editing portions of it.  I would like to use Server Side Includes for the code that is common on several pages of the website.  I wrote some test code and it works as viewed via Dreamweaver; however, when viewing the changed web page the code isn't included.
I've come to the conclusion that Server Side Includes haven't been enabled.  I would like to examine the httpd.conf file (or the .htaccess file) to confirm this but I don't know how to look for it.  I've used WinSCP and FileZilla to FTP into the drive but can't find either file.  I thought these files might be under the /mnt or /mnt/array1 folders but I can't find anything I'm looking for.
Obviously, I'm a novice at this and would appreciate any help.
Thanks in advance.