apexcharts-card write chart value to custom variable

Configuration Frontend
1

hey guys,
i implemented a apexcharts-card on my frontend.
Everything works great so far, but i would like to implement a feature and unfortunately i can not get it to work.
When i click on the chart, i would like to set a custom variable to the chart value i clicked on.
I tried a couple of ways to get it to work, but without any luck.

Could someone please help me?

This is my configuration right now:

type: custom:apexcharts-card
hours_12: false
header:
  show: true
  show_states: true
graph_span: 48h
span:
  start: day
now:
  show: true
  label: jetzt
series:
  - entity: sensor.epex_spot_data_net_price
    header_actions:
      tap_action:
        action: navigate
        navigation_path: /dashboard-test/1
    show:
      extremas: time
      in_header: before_now
    name: aktueller Preis
    type: line
    curve: stepline
    extend_to: end
    data_generator: |
      return entity.attributes.data.map((entry, index) => { return [new
      Date(entry.start_time).getTime(), entry.price_ct_per_kwh];
      });
    color_threshold:
      - value: 15
        color: green
      - value: 18
        color: "#04822e"
      - value: 20
        color: "#12A141"
      - value: 22
        color: "#79B92C"
      - value: 24
        color: "#C4D81D"
      - value: 26
        color: "#F3DC0C"
      - value: 28
        color: red
experimental:
  color_threshold: true
yaxis:
  - id: preis
    decimals: 0
    apex_config:
      title:
        text: cent/kWh
      tickAmount: 10
apex_config:
  tooltip:
    x:
      show: true
      format: HH:00 - HH:59

resulting in that look:
Screenshot 2024-12-28 215722

2

is there absolutely nobody who did that before?
please help

3

For me at least, it is not clear what you mean with “set a custom variable to the chart value i clicked on”