Elixir - Handling a large query error and sending response

so as part of my software implementation I have a voice note upload function, I was writing tests and as part of it I wrote the following test for larger files and hopefully I want to have it throw a 413 Entity too large error,

this is the test I've wrote down

        test "send VN fail when too large", %{conn: conn} do
        Couchdb.Connector.Storage.storage_down(CouchdbHelperFunctions.db_props(@create_user_data.username))
        {:ok, user_data} = UserManager.create_user(@create_user_data)
        {:ok, token, _} = UserManager.authenticate(@create_user_data.username, @create_user_data.password)
        conn = put_req_header(conn, "authorization", "Bearer " <> token)
        {:ok, chatroom_data} = ChatroomManager.create_chatroom(user_data.id, "test")

        {:ok, voice_note_file} = File.read("test/4051.mp3")

        conn = put_req_header(conn, "content-type", "application/octet-stream")

        response = conn
        |> post chatroom_chatroom_path conn, :send_voice_note, chatroom_data.id, body: voice_note_file

        assert response.status == 413
    end

The result I'm getting on the fail is this

 1) test send_voice_note/2 send VN fail when too large (BackendWeb.ChatroomControllerTest)
 test/backend_web/controllers/chatroom_controller_test.exs:233
 ** (Plug.Conn.InvalidQueryError) maximum query string length is 1000000, got a query with 1242763 bytes
 code: |> post chatroom_chatroom_path conn, :send_voice_note, chatroom_data.id, body: voice_note_file
 stacktrace:
   (plug) lib/plug/conn.ex:845: Plug.Conn.fetch_query_params/2
   (plug) lib/plug/parsers.ex:256: Plug.Parsers.call/2
   (backend) lib/backend_web/endpoint.ex:1: BackendWeb.Endpoint.plug_builder_call/2
   (backend) lib/backend_web/endpoint.ex:1: BackendWeb.Endpoint.call/2
   (phoenix) lib/phoenix/test/conn_test.ex:224: Phoenix.ConnTest.dispatch/5
   test/backend_web/controllers/chatroom_controller_test.exs:245: (test)

What I tried is adding this to my error_view.ex in hopes of having it throw a response

  defimpl Plug.Exception, for: Plug.Conn.InvalidQueryError do
def status(_exception), do: 413
end

and it didn't work out. Any Ideas if i'm adding it in the wrong place?