Get stream of closed captions from RTMP stream

Hi, videoengineering noob here that needs help. I have a conference setup where multiple rooms stream live video via Zoom to YouTube. I want to provide a way for the participants in the rooms can view live captions in their mobile devices by scanning a QR code that gives them the URL to a server that streams captions.

There are companies like Syncwords that provide this service by re-captioning the audio streams. I ideally want to use the captions Zoom is already creating and also the service was prohibitively expensive. Is there a good software for getting the captions from the RTMP stream (which can be sent via the "Zoom Live Streaming app") and show it on a standalone website? I'm okay with writing some code for example for the website.