intrument_channel.ex

defmodule WSSWeb.IntrusmentChannel do
  use Phoenix.Channel

  def join("instrument_info:" <> trading_symbol, _message, socket) do
    IO.puts("Joined topic instrument_info:#{trading_symbol}")
    {:ok, socket}
  end

  def terminate(reason, socket) do
    IO.puts("Closing socket #{inspect(reason)} , #{inspect(socket.topic)}")
  end
end

react-phoenix-socket.tsx

useEffect(() => {
  let socket = new Socket("ws://localhost:4000/socket");

  socket.connect();

  let channel = socket.channel(`instrument_info:ETHBTC`, {});
  channel
    .join()
    .receive("ok", (res) => {
      console.log("Joined Instrument Successfully", res);
    })
    .receive("error", (res) => {
      console.log("Join Error", res);
    });

  channel.on("new_ltp", (res) => {
    console.log(res);
  });
}, []);

user_socket.ex

defmodule WSSWeb.UserSocket do
  use Phoenix.Socket

  # Channel
  channel "instrument_info:*", WSSWeb.IntrusmentChannel

  @impl true
  def connect(_params, socket, _connect_info) do
    {:ok, socket}
  end

  @impl true
  def id(_socket), do: nil
end

# first arg is topic, sec is event,third is payload send to client
# WSSWeb.Endpoint.broadcast "instrument_info:ETHBTCS","new_ltp",%{"ltp"=> 6.103}
#  then client will recieve by sockey.channel("instrument_info:ETHBTC")
#  channel.on("new_ltp",(res)=>res) // {ltp: 6.103}

# channel.on("event")