How can I customize the Interactive Avatar to use my own server-side API instead of the default LLM?

I want to change https://github.com/HeyGen-Official/InteractiveAvatarNextJSDemo to get responses to user text or voice queries from my server-side API instead of from the HeyGen LLM. That is, I want the user to be able to provide either text input or voice input and have it sent to my API endpoint which will return text that the avatar should speak.

I think I just have to slightly edit the InteractiveAvatar.tsx and the InteractiveAvatarTextInput.tsx files. But, I am not sure what changes I need to make.

Muhammad Irfan asked a similar question (https://docs.heygen.com/discuss/67206dc0ec7f44001faf84d7) 17 days ago but received a response that he indicated did not answer his question.

I'd REALLY appreciate a response. This product is so, so cool. I am dying to get it set up!