Tomorrows price unavailable with Nordpool core integration

I’m in the process of moving from the custom component for Nordpool to the new core integration. Besides having issues displaying today and tomorrow’s price on a chart (see here), I’m also trying to follow the examples form the official doc.
When testing “tomorrow’s lowest price” in the template editor, I get

‘tomorrow_price’ is undefined

I used the exact same code as the Example, just changed my config_entry and SE3 to SE4.

template:
  - trigger:
      - trigger: time_pattern
        minutes: /10
      - trigger: homeassistant
        event: start
    action:
      - action: nordpool.get_prices_for_date
        data:
          config_entry: 01JHZHJ9EMYV8JA28490CH5GEE
          date: "{{ now().date() + timedelta(days=1) }}"
          areas: SE4
          currency: SEK
        response_variable: tomorrow_price
    sensor:
      - name: Tomorrow lowest price
        unique_id: se4_tomorrow_low_price
        state: >
          {% if not tomorrow_price %}
            unavailable
          {% else %}
            {% set data = namespace(prices=[]) %}
            {% for state in tomorrow_price['SE4'] %}
              {% set data.prices = data.prices + [(state.price / 1000)] %}
            {% endfor %}
            {{min(data.prices)}}
          {% endif %}
        attributes:
          data: >
            {% if not tomorrow_price %}
              []
            {% else %}
              {% set data = namespace(prices=[]) %}
              {% for state in tomorrow_price['SE4'] %}
                {% set data.prices = data.prices + [{'start':state.start, 'end':state.end, 'price': state.price/1000}] %}
              {% endfor %}
              {{data.prices}}
            {% endif %}

Anything I do wrong? Or is this a bug with the integration?

I didn’t find any information on the actions available with the integration (e.g. get_prices_for_date), where are these documented?

Is tomorrows prices available then?
Can you look at the entity and see if there are any prices tomorrow?

They should be.
If I got to Developper tools > Actions I can get them:

But under entity states, I can’t see anything:

Check the state by searching for Tomorrow lowest price