Audio stream from microphone outbound

I would like to build a Google Nest mini like device.
The idea is that a Raspberry Pi Zero W with a USB microphone constantly steams the audio to a Pi 4. Pi 4 listens for a trigger word via voice2json. Once the trigger word is found, it switches to STT and sends the text to ChatGPT for interpretation.

I only can't find out how to stream audio form one Pi to another. If possible with Node Red.

Any other ideas how to solve this are welcome too.

Have a look at Johannes Kropf his node-red-contrib-voice2json node. In the examples there's a sample Audio_over_http maybe this can help you in the right direction.

Btw, not used it myself, so no experience.