How to get `/stream` serverless endpoint to "stream"?

from time import sleep
import runpod


def handler(job):
    job_input = job["input"]["prompt"]

    for i in job_input:
        sleep(1)  # sleep for 1 second for effect
        yield i


runpod.serverless.start(
    {
        "handler": handler,
        "return_aggregate_stream": True,  # Ensures aggregated results are streamed back
    }
)

import runpodSdk from "runpod-sdk";

async function main() {
  const runpod = runpodSdk(RUNPOD_API_KEY);
  const endpoint = runpod.endpoint(ENDPOINT_ID);
  const result = await endpoint.run({
    input: {
      prompt: "Hello, World!",
    },
  });

  console.log(result);

  const { id } = result;
  for await (const result of endpoint.stream(id)) {
    console.log(`${JSON.stringify(result, null, 2)}`);
  }
  console.log("done streaming");
}