Apex chart Single value

type: custom:apexcharts-card
apex_config:
  chart:
    height: 250px
experimental:
  color_threshold: true
graph_span: 1h
header:
  show: true
  title: Integral change
  show_states: true
  colorize_states: false
yaxis:
  - decimals: 2
series:
  - entity: sensor.integral_change_roomtemp
    yaxis_id: first
    unit: C/h
    color: red
    stroke_width: 1
    type: area
    extend_to: now
    color_threshold:
      - value: 0
        color: orange
    show:
      name_in_header: false
    float_precision: 2