No file stored or storage_dir scope == nil about arc_ecto HOT 7 CLOSED

defmodule Blog.UserApi do
  use Maru.Router

  params do
    optional :name, type: String
    optional :avatar, type: File
  end
  put "/user" do
    token = List.first(get_req_header(conn, "auth-token"))
    user = Blog.Repo.get_by(Blog.User, auth_token: token)

    IO.inspect params
    changeset = Blog.User.changeset_update(user, params)

    case Blog.Repo.update(changeset) do
      {:ok, user} ->
        conn
        |> put_status(:ok)
        |> json(Blog.CurrentUserEntity.serialize(user))
      {:error, _changeset} ->
        conn
        |> put_status(:unprocessable_entity)
        |> json(%{error: "Invalid request"})
    end
  end
end

  @required_fields ~w()
  @optional_fields ~w(name)

  @required_file_fields ~w()
  @optional_file_fields ~w(avatar)a  # <-- added 'a' here