Add streaming to langchain response in nodejs

I built a server that uses langchain to return a response. I returns the response in a single batch, but I want to enable streaming. This is the documentation: https://js.langchain.com/docs/modules/agents/how_to/streaming My github repo (You need to modify this code): https://github.com/hectordiazgomez/task_streaming/blob/main/index.js