Adding a button to an existing react app

Hello, so I am using the react app provided by this git link, GitHub - jitsi/jitsi-meet: Jitsi Meet - Secure, Simple and Scalable Video Conferences that you use as a standalone app or embed in your web application., and I want to add an additional button to the toolbox and due to me having no React Experience I have no clue how to start. Does anyone have/know of a comprehensive guide, I can use to help me?

I have gone through this page many times before but I couldn’t figure out how implement a button with a new function that I add since I could not figure out the html file, or the file that produces the html of the toolbox within the files in the git link from the OP

the image here I edited using paint, for I have no clue how to implement this with the code provided

The code is here: jitsi-meet/react/features/toolbox at master · jitsi/jitsi-meet · GitHub
You can see how other buttons are implemented.

So I was attempting to implement a button that just changes the icon on said button (so like how the icon of the videomuting button changes upon click) so to if I use the VideoMuteButton.js within the components folder in the link you provided what parts are necessary?

You pass toggled: true to the ToolboxIitem as props

So I have did all of this and build/make the app, but I didn’t see a new button appear. Which files do I have go to to add the location of the new files I made somewhere else to make the button appear? I ask since this seems to me what I am missing