[Question] How to use local video in prejoin room so that we can use Video Processor for Virtual Background/Blur

[tirth0]

I am trying to create a Pre Join lobby in my react native app. I am wondering how to use tracks produced by livekit (createLocalTracks etc) to access camera and microphone such that:

1. I can get permissions in the lobby screen if needed.
2. Use VideoProcessor to generate Virtual Background/Blur effect in the Prejoin lobby.

Thank you!