Automations with attribute

Hi

Trying to make an automation from Nordpool. I want to activate a switch when attribute
“low price” is true and off when attribute low price is false. But i dont get it working…

Have this in my automation now

alias: Low_price
description: Start when low price is true
trigger:
  - platform: state
    entity_id:
      - sensor.nordpool_elpris
    attribute: low price
    to: "true"
condition: []
action:
  - type: turn_on
    device_id: 931b0610ee7a4fbeb8b86df89e956d9d
    entity_id: switch.fcnsterlampor_v_rum
    domain: switch
mode: single