I want to develop a Flutter video chat app using WebRTC and Firebase, with the ability to make calls using mobile numbers. Could anyone provide a step-by-step guide on how to establish connections between multiple devices and detail the necessary requirements?

I’m building a Flutter video chat app with one-to-one and one-to-many calls, and I’m struggling to implement the logic for handling group calls. Any suggestions on how to approach this with real-time messaging? i dont wanna use any 3rd party SDKs,i use firebase as backend and WebRTC now want call recording functionality too?