How can I change the backend code?

I want to use jitsi react native app in one of my projects with little changes in the backend login.

I want to get the video of only specific participants. Otherwise, participant can only join and listen and perform other tasks (like, comment, etc.).

I have reviewed the code in react folder and tried to make some customization in UI. I successfully changed it.

Regarding backend, I found in this blog post Jitsi Meet backend modification and adding custom logic - #2 by damencho

that we can change it in persody-plugins (jitsi-meet/resources/prosody-plugins at master · jitsi/jitsi-meet · GitHub)

But i didn’t get the request flow that how request is going from react native to this module.

Do you have any documentation about it? OR can you please explain it.