Receive Data from Websocket ActionCable + Postman

Question

I have the following code to setup my websocket implementaion using ActionCable in a Rails API project

routes.rb

mount ActionCable.server => '/cable'

application.rb

config.action_cable.mount_path = nil

development.rb

config.action_cable.url = "ws://localhost:3001/cable"
config.action_cable.disable_request_forgery_protection = true

channels/application_cable/channel.rb

module ApplicationCable
  class Channel < ActionCable::Channel::Base
  end
end

channels/jobs_channel.rb

class JobsChannel < ApplicationCable::Channel
  def subscribed
    stream_from "jobs_channel"
  end

  def unsubscribed
    # Any cleanup needed when channel is unsubscribed
  end
end

using redis. i have my cable.yml

development:
  adapter: redis
  url: "redis://localhost:6379/0"

test:
  adapter: test

production:
  adapter: redis
  url: <%= ENV.fetch("REDIS_URL") { "redis://localhost:6379/1" } %>
  channel_prefix: <your_app_name>_production

and because i want to have both my rails server and my websocket server running at the same time, i setup a file cable/config.ru

require ::File.expand_path('../../config/environment',  __FILE__)
Rails.application.eager_load!

run ActionCable.server

Now i start my rails server as rails s and start my websocket server as bundle exec puma -p 3001 cable/config.ru. I also make sure my redis server is running.

On postman, i setup like this and it is able to connect to the websocket server

To be able to send data to the websocket, i should be able to do something like this

serialized message = {"data": "Hello world"}
ActionCable.server.broadcast("jobs_channel", serialized_message)

But it seems not to be working. I cannot seem to be able to pass data via the websocket. What am i doing wrong?

Would appreciate if anyone can point me in the right direction.

Thanks