How to do chroma keying on a live WebRTC video

So I am using Agora WebRTC to get the live webcam feed of a person, and I can change this person’s background to a greenscreen using Virtual Background in Agora itself.

What I am trying to achieve is that within Unity, I am able to chroma key the greenscreen off the person’s background and get their webcam feed with only the person visible, and the rest of the surface becoming transparent.
I will be pushing this entire transparent person feed to a VR device.

I have tried using the chroma key shader provided on : link:ChromaKey
But, I am not sure if what I am trying is even possible. Is there any other WebRTC that provides this functionality inbuilt ??

I am willing to pay upto $50 for help or for a software that will achieve what I am trying to do.