How can I test and preview the mic and camera?

I want to create a page similar to the Jitsi Meet instant conference page where you get redirected to a new page where you can enter your name before joining the room. On this page a user can test his microphone and camera. Hopefully, I’m looking at the right documentation, I’m looking at the iFrame API docs (I don’t really see any other docs for a web app), I’m just not sure which functions to use. Would it be isAudioAvailable and isVideoAvailable? Any other functions, commands or events I would need to achieve this?

you mean this in [domain]-config.js, I guess?

    // When 'true', it shows an intermediate page before joining, where the user can configure their devices.
    prejoinPageEnabled: true,

It might be, let me look into this.

@ keithbayer
So this helps, but what I want to do is copy the microphone and camera HTML code into another file in my application. Of course my application isn’t using React on the frontend, so I would need the Javascript code (functions or commands) that Jitsi uses for this functionality.