Using manage_relationship with nested relationships

defmodule Patient do
  use Ash.Resource, data_layer: AshPostgres.DataLayer

  postgres do
    table "patients"
    repo Repo
  end

  attributes do
    uuid_primary_key(:id)
    attribute(:first_name, :string)
    attribute(:last_name, :string)
    timestamps()
  end

  relationships do
    has_many :event_series, EventSeries
  end
end

defmodule EventSeries do
  use Ash.Resource, data_layer: AshPostgres.DataLayer

  postgres do
    table "event_series"
    repo Repo
    
    custom_indexes do
      index [:patient_id, :initial_date], unique: true
    end
  end

  attributes do
    uuid_primary_key(:id)
    attribute(:initial_date, :date)
    timestamps()
  end

  relationships do
    belongs_to :patient, Patient, allow_nil?: false
    has_many :exams, Exam
  end
end

defmodule Exam do
  use Ash.Resource, data_layer: AshPostgres.DataLayer

  postgres do
    table "exams"
    repo Repo
  end

  attributes do
    uuid_primary_key(:id)
    attribute(:performed_on, :date)
    timestamps()
  end

  relationships do
    belongs_to :event_series, EventSeries, allow_nil?: false
  end
end

Exam
|> Ash.Changeset.for_create(:create, %{performed_on: performed_on})
|> Ash.Changeset.manage_relationship(:event_series, %{patient_id: patient_id, initial_date: examdate}, type: :append_and_remove, on_no_match: :create)
|> Api.create()