Guest´s Volume Master Button on Jitsi based platform -- 2

We are a theatre company looking to use jitsi to live stream the performances. Since we specialize in children´s plays, we would like to have an interactive platform, in which the performers interact with audience members by listening to each other on real time. (the only image our guests can see is the administrator´s camera, hence the performance). To achieve this interaction, we need to have control of the volume in which our guests listen to each other.

The project consists on developing a master volume button on jitsi itself in which the administrator can lower or raise the volume level that guests listen to each other, without affecting the volume of the administrator (performance), managed with the up/down keys on keyboard.

Also, we would need the latest version of Jitsi, everything on the website:
escenario.teatrovirtual.org for which we already have a server with Digital Ocean.