Hey I am trying to send an audio recording from my react-native android app the request looks like this:

let data = new FormData();
        data.append("recording", {
          uri: rec._fsPath,
          type: "audio/mp4",
          name: "testRec",
          challenge_id: 1,
          user_id: 1,
          mod_score: 3
        });
        console.log(data);
        axios
          .post(
            config.API_URL + "recordings",
            { data },
            { headers: { Authorization: "Bearer " + this.props.auth.token } }
          )
          .then(res => res.data);

the params when arrive they look like this:

This typically happens when there is aparameter mismatch but may also happen when any of the other action arguments do not match. The request parameters are:
%{"data" => %{"_parts" => [["recording", %{"challenge_id" => 1, "mod_score" => 3, "name" => "testR ec", "type" => "audio/mp4", "uri" => "/data/user/0/com.cobrn/files/filename.mp4", "user_id" => 1}]]} }

and my api is expecting recording_params that goes here:

with {:ok, %Recording{} = recording} <- Web.create_recording(recording_params)

that goes here:

def create_recording(attrs \\ %{}) do

    %Recording{}
    |> Recording.changeset(attrs)
    |> Repo.insert()
  end

that goes to my schema that looks like this:

defmodule Userteam1.Web.Recording do
  use Ecto.Schema
  use Arc.Ecto.Schema
  import Ecto.Changeset

  schema "recordings" do
field(:path_to_recording, Userteam1Web.Recording.Type)
field(:mod_score, :integer)
belongs_to(:user, Userteam1.Web.User)
belongs_to(:challenge, Userteam1.Web.Challenge)
has_many(:comment, Userteam1.Web.Comment)

timestamps()
  end

  @doc false
  def changeset(recording, attrs) do
recording
|> cast(attrs, [:challenge_id, :user_id, :mod_score])
|> cast_attachments(attrs, [:path_to_recording])
|> validate_required([:path_to_recording])
  end
end

as you can see it should cast the attachment, as the documentation and examples showed for ARC and ARC-ecto but either the request is wrong in some form, or is it not attached, does append do what attach wants to take?
I know that this might be a lot to read, but I would really appreciate some help with this issue, and I think this could be good resource for other devs too in the future.