Interactive Avatar Streaming - use own OpenAI / Chat Service

Hello,

We have our own AI chat streaming service (AWS fargate + OpenAI realtime API) as we have custom functions and code to run to generate responses.

How do we switch out where in the demo project https://github.com/HeyGen-Official/InteractiveAvatarNextJSDemo that OpenAI is getting called to generate the chat response?

We want to switch from where the openai streaming call is made, to our own websocket fargate service, but I don't see any API calls to OpenAI in the project.