Jitsi meet chat button

Hi, totally new to jitsi meet… Which file to look into for chat button behavior? Especially, would like to see the code where the sliding panel opens when onclick is done

To be precise, my requirement is to have a new button, and onclick, need to open a sliding panel. Similar to chat button Onclick
But not able to place the source code where sliding panel for chat button is created and how it is rendered
Appreciate help