compiles and runs from iex, but how to run outside that

lib/queen.ex

@@ -1,18 +1,12 @@
 defmodule Queen do
-  @moduledoc """
-  Documentation for `Queen`.
-  """
+  import Plug.Conn
 
-  @doc """
-  Hello world.
+  def init(opts) do
+    opts
+  end
 
-  ## Examples
-
-      iex> Queen.hello()
-      :world
-
-  """
-  def hello do
-    :world
+  def call(conn, _opts) do
+    :logger.debug("saying hello")
+    send_resp(conn, 200, "hello from queen")
   end
 end

lib/queen/application.ex

@@ -8,6 +8,7 @@ defmodule Queen.Application do
   @impl true
   def start(_type, _args) do
     children = [
+      {Bandit, plug: Queen}
       # Starts a worker by calling: Queen.Worker.start_link(arg)
       # {Queen.Worker, arg}
     ]

mix.exs

@@ -14,16 +14,14 @@ defmodule Queen.MixProject do
   # Run "mix help compile.app" to learn about applications.
   def application do
     [
-      [applications: [:logger, :ecto_sqlite3, :ecto, :bandit, :plug]]
-      # extra_applications: [:logger]
+      # extra_applications: [:logger, :ecto_sqlite3, :ecto, :bandit, :plug]
+      extra_applications: [:logger]
     ]
   end
 
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
-      # {:dep_from_hexpm, "~> 0.3.0"},
-      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
       {:bandit, "~> 1.2"},
       {:plug, "~> 1.5"},
       {:ecto_sqlite3, "~> 0.15"},