How do I write a Exq worker here?

But here handle call accepts only three arguments. You’re not using “conn” anywhere. You might have to explain that also.

 def set(pid, key, value) do
    GenServer.call(pid, {:set, key, value})
 end

  # handle call for set function
  def handle_call({:set, key, value}, _from, state) do
    reply = Redix.command(state, [conn, key, value])
    {:reply, reply, state}
  end