Loading object field with different data sources with absinthe dataloader

Hi, does anyone knows how to do lazy loading with multiple data sources using absinthe data loader?

  object :user do
    # always known
    field :id, non_null(:id), description: "User ID"

    # resolved using API
    field :username, non_null(:string), description: "Username of the user"
    field :avatar, :string, description: "Avatar of the user"
    # resolved using DB
    field :last_seen, :datetime, description: "Last seen date of user"

I ve the following object, which has certain fields to be loaded from an external API
I thought to use dataloader on loading the object from API and reusing across the query

So there need to be field level resolvers from username and avatar(both should use dataloader to fetch the user by id and return appropriate data). Also sometimes relevant data can be present already

But as i remember, If i call dataloader.run its not batching requests, how we can use dataloader with batching?(user_id = 1 should be only loaded 1 time during the query)

My current code

  def resolve_username(%{username: username}, _args, _resolution)
      when is_binary(username) do
    {:ok, username}

  def resolve_username(parent, _args, resolution) do
    loader = resolution.context.loader
    user_id = parent.id

    # what to do here to load user from API with batching

  def load_user_by_id(loader, id) do
    |> Dataloader.load(:user, :user, id)
    |> on_load(fn loader ->
      |> Dataloader.get(:user, :user, id)
      |> case do
        %UsersBulkResponse.User{} = user ->
          {:ok, user}

        %UsersBulkResponse.Error{error: err} ->