How to insert array of maps in Ecto

I have a model with field of type array defined:

defmodule QsiSearchService.Features.FeatureProperties do
  use Ecto.Schema
  import Ecto.Changeset
  alias QsiSearchService.Features.{FeatureProperties, FeatureType}

  @primary_key {:id, :binary_id, autogenerate: true}
  @foreign_key_type :binary_id
  schema "feature_properties" do
    field :fields, {:array, :map}
    belongs_to :feature_type, FeatureType

    timestamps()
  end

  @doc false
  def changeset(%FeatureProperties{} = feature_properties, attrs) do
    feature_properties
    |> cast(attrs, [:fields, :feature_type_id])
    |> validate_required([:fields, :feature_type_id])
  end
end

When I try creating a record:

@feature_properties_attrs %{fields: [
    %{"name" => "PROGRESS_STATUS", "type" => "string"},
    %{"name" => "VOLTAGE", "type" => "number"}
  ]}

{:ok, feature_properties} = 
      @feature_properties_attrs
      |> Map.put(:feature_type_id, created_feature_type.id)
      |> Features.create_feature_properties()

I get the following error:

 ** (ArgumentError) Postgrex expected a binary, got %{"name" => "PROGRESS_STATUS", "type" => "string"}. Please make sure the value you are passing matches the definition in
 your table or in your query or convert the value accordingly.

Is this kind of operation possible, or do I have to create this schema using embeds?

Thanks