Protocol Jason.Encoder not implemented for {:ok, #Money<:USD, 20000>} of type Tuple, Jason.Encoder protocol must always be explicitly implemented

Hello, I have a very newbie question if anyone knows.

I’m using this libraries

{:ex_money, "~> 5.5.1"},
{:ex_money_sql, "~> 1.4.4"}

to deal with Money. First time I work with Money types because I was doing it using only decimals.

I configured this libraries well, I know because I can seed data with no problem using this:

Repo.insert!(%InnovationProject{
  budget: Money.new(:USD, 7800),
  term: 2
})

and receiving no errors at that time. And when doing GET requests the format is a Money type in the result.
So, with that out of the way, I have the following Ecto.Schema on Phoenix Framework:

schema "innovation_projects" do
    field :budget, Money.Ecto.Composite.Type
    field :term, :decimal
    field :anual_cost, Money.Ecto.Composite.Type, virtual: true

    timestamps()
  end

My changeset:

def changeset(innovation_project, attrs) do
    innovation_project
    |> cast(attrs, [
      :budget,
      :term
    ])
    |> validate_required([
      :budget,
      :term
    ])
    |> calculate_anual_cost()
  end

And calculate_anual_cost function looks like this:

 defp calculate_anual_cost(changeset) do
    budget = get_change(changeset, :budget)
    term = get_change(changeset, :term)

    changeset
    |> put_change(:anual_cost, budget |> Money.div(term))
  end

Now, I think that there’s no problem here. But my error comes when I want to show anual_cost on my views

So, my innovation_project_view.ex looks like this:

def render("innovation_project.json", %{innovation_project: innovation_project}) do
    %{
      budget: innovation_project.budget,
      term: innovation_project.term,
      anual_cost: innovation_project.anual_cost
    }
  end

Eyes on anual_cost: innovation_project.anual_cost because that’s the line giving me this issue:

protocol Jason.Encoder not implemented for {:ok, #Money<:USD, 20000>} of type Tuple, Jason.Encoder protocol must always be explicitly implemented. This protocol is implemented for the following type(s): Money, Cldr.LanguageTag, Ecto.Association.NotLoaded, Ecto.Schema.Metadata, BitString, List, Integer, Any, Date, Map, NaiveDateTime, Atom, Jason.Fragment, DateTime, Decimal, Time, Float

So, my view can show budget, which is a Money type but the generated virtual field anual_cost can’t be shown. How can I show my anual_cost?

One more thing:

iex> Money.div Money.new(:USD, 200), 2
    {:ok, Money.new(:USD, 100)} 

Thanks in advance