HA says configuration error

I created helpers for this and tried this to the end of the sensor:

        {{ ns.highest_price }}
        service: input_number.set_value
        data:
          value: "{{ ns.highest_price | float(0)}}"
        target:
            entity_id: input_number.nord_highest_cost
        service: input_number.set_value
        data:
          value: "{{ ns.second_highest_price | float(0)}}"
        target:
          entity_id: input_number.nord_2nd_highest_cost
        service: input_datetime.set_datetime
        data:
          time: "{{ ns.expensive_time | timestamp_custom('%H:%M', true)}}"
        target:
          entity_id: input_datetime.nord_highest
        service: input_datetime.set_datetime
        data:
          time: "{{ ns.second_expensive_time | timestamp_custom('%H:%M', true)}}"
        target:
          entity_id: input_datetime.nord_2nd_highest

This aint working either… all helpers are still null
I am finding a lot of ways this is NOT working :wink:

This is why AI is bad, it lies to you. This will create the sensor.

template:
- trigger:
  - platform: state
    entity_id: sensor.nordpool_kwh_fi_eur_3_10_0
  action:
  - variables:
      calculation: >
          {% set hours_ahead = states('input_number.hours_ahead') | int %}
          {% set current_time = as_timestamp(now()) %}
          {% set ns = namespace(times=[], prices=[], highest_price=0, second_highest_price=0, expensive_time=now(), second_expensive_time=now(), hour_counter=0) %}
          {% set today = state_attr('sensor.nordpool_kwh_fi_eur_3_10_0','raw_today') %}
          {% for hours in today -%}
            {% if ns.hour_counter < hours_ahead -%}
              {% set retrieved_time = as_timestamp(as_local(hours.start)) %}
              {% if retrieved_time > current_time - 3600 %}
                {% set retrieved_price = (hours.value | float(0) + states('input_number.nordpool_additional_cost') | float(0)) %}
                {% if retrieved_price > ns.highest_price %}
                  {% set ns.second_highest_price = ns.highest_price %}
                  {% set ns.second_expensive_time = ns.expensive_time %}
                  {% set ns.highest_price = retrieved_price %}
                  {% set ns.expensive_time = retrieved_time %}
                {% elif retrieved_price > ns.second_highest_price %}
                  {% set ns.second_highest_price = retrieved_price %}
                  {% set ns.second_expensive_time = retrieved_time %}
                {% endif %}
                {% set ns.hour_counter = ns.hour_counter + 1 %}
              {% endif %}
            {% endif %}
          {% endfor %}
          {% if ns.hour_counter < hours_ahead -%}
            {% set tomorrow = state_attr('sensor.nordpool_kwh_fi_eur_3_10_0','raw_tomorrow') %}
            {% for hours in tomorrow %}
              {% if ns.hour_counter < hours_ahead %}
                {% set retrieved_time = as_timestamp(as_local(hours.start)) %}
                {% if retrieved_time > current_time - 3600 %}
                  {% set retrieved_price = (hours.value | float(0) + states('input_number.nordpool_additional_costs') | float(0)) %}
                  {% if retrieved_price > ns.highest_price %}
                    {% set ns.second_highest_price = ns.highest_price %}
                    {% set ns.second_expensive_time = ns.expensive_time %}
                    {% set ns.highest_price = retrieved_price %}
                    {% set ns.expensive_time = retrieved_time %}
                  {% elif retrieved_price > ns.second_highest_price %}
                    {% set ns.second_highest_price = retrieved_price %}
                    {% set ns.second_expensive_time = retrieved_time %}
                  {% endif %}
                {% set ns.hour_counter = ns.hour_counter + 1 %}
                {% endif %}
              {% endif %}
            {% endfor %}
          {% endif %}
          {{ dict(times=ns.times, prices=ns.prices, highest_price=ns.highest_price, second_highest_price=ns.second_highest_price, expensive_time=ns.expensive_time.isoformat(), hour_counter=ns.hour_counter, second_expensive_time=ns.second_expensive_time.isoformat()) }}
  sensor:
  - name: NordPool Most Expensive Times
    unique_id: a27dbebc-12a3-4658-93cf-3f61a8fc6035
    icon: mdi:clock
    device_class: timestamp
    state: "{{ calculation.expensive_time }}"
    attributes:
      most_expensive: "{{ calculation.highest_price }}"
      most_expensive_at: "{{ calculation.expensive_time }}"
      second_most_expensive: "{{ calculation.second_highest_price }}"
      second_most_expensive_at: "{{ calculation.second_expensive_time }}"

Thank You Petro, how should I implement this into my HA?
currently I have in my configuration file

template: !include templates.yaml
and all the sensors are built in temlates.yaml starting with:

- sensor:
    ##### Consuming NordPool Energyprices vat 24% ##################################
    - name: "NordPool Energyprices"
      unique_id: 472d8ec19-5db5-459b-8366-c0557c864c06
      icon: mdi:currency-eur
      unit_of_measurement: "€"
      state: >
        {{ states('sensor.nordpool_hinta')}}
      attributes:
      ......
    - name: "next sensor"
    - name: "next sensor2"
    - name: "next sensor3"
    ...

Now I can not include that as is to templates.yaml since it includes only sensors

and sorry - i might be too newbie for what i am trying…

Hey, I take it this would go to configutations files - tell me how can i still use templates.yaml with this? I have in my configuration file
template: !include templates.yaml
I cant have multiple template: lines…

Should I move all sensors from template.yaml to configurations.yaml or how should i modify this in order to run it in template.yaml file with the rest of the sensors?

put it in your templates.yaml file and remove the first template: line from the example I posted. Also, make sure the spacing lines up with the other contents in your template file.