Due to security measures in many browsers, a web application cannot play any audio without the user interacting with the application first.
To resolve this issue, whenever you load our extension in your Twitch live dashboard, make sure to click anywhere inside the extension view (switch between activity and queue views, or open the quick settings view for example) and the security measure for audio playback will be lifted.
We are currently working on improving the User Experience for live view load to mitigate this problem.