Docker-Jitsi - prevent ALL pop-in messages

Hello guys!

Are there features to completely disable the microphone?
We use it as a desktop share, but talk through our telephone system.
Unfortunately I always get the message that no microphone was found. I would like to stop this message!

On Github I could find the error output in the middleware.js file: “jitsi-meet-master\jitsi-meet-master\react\features\base\devices\middleware.js”
We use Jitsi as a finished Docker installation. Unfortunately, I cannot find the middleware.js file there.

Is there a way to prevent ALL messages in a Docker Jitsi via a global configuration?

Thanks