A microphone or camera must be visible to the browser since xroom.app is running inside of it. It should run fine on all main platforms (Windows, Linux, OSX, Android and iOS*) as long as you are using a modern browser. Please check your browser configurations and permissions first. Otherwise, try another browser. *All iOS users should be aware that Apple only provides cam/mic access outside of Safari starting with iOS 14.3 so ensure to update. For more help, please check out this link here.