amazon web services – How to stream to an AWS ECS container (RTMP)?

I am trying to generate transcriptions for a live-stream video. I found this aws sample on Amazon IVS Auto-captions Web demo which seems similar to my use case.

But here it says that we need to stream to an ECS container. I searched a lot but couldn’t find any resource explaining how to do that.

Can someone point me to some resources (docs/articles/videos) from where I can understand how to send a live stream to an ECS container so that I can send it further to AWS Transcribe? Or is there some other architecture that I can use to generate transcriptions for a live stream?