How SQL Database connects to Extension_additional.conf?

Hi everyone,
My name is Malisa,
I’m a student and I have a project in my university about editing some values on my Asterisk system with a new website for clients.
I start creating a new website to edit database “asterisk” of FreePBX, and it works well…
But it doesn’t affect with Asterisk system or file “extension_additional.conf”.

For example:
I change a announcement of IVR for extension 101 in database, but it not affect file extension_additional.conf
I know it needs some script to dot it but I don’t know where it is because I am a beginner…
In file admin/config.php or somewhere?
It’s so difficult for me, please help me! :((

you can find it at admin/view/freepbx_reload.php
But I don’t know which function affects it!