How to add new event to Iframe API

Hello Fellow Jitsters,

Thank you for making such a great product.
I installed my own Jitsi Meet server with jibri for recording purpose a week ago.

I am using IFrame API on the frontend side.
I can start the recording but I don’t want to play that sound “Recording is on” but to make a custom notification for the user.
I would like to add few custom event to the API, something like “recording-started” and “recording-stopped”. I searched the code but I got lost and I need your help.

What is the right way to extend the API and to add these two events?