Template with Calendar Events in Rss Feed

Hello,

I want to display the agenda text of the next days on my Divoom device.

I can send a notifcation with the correct value, but do not know how to pass the Agenda Text to my template. How can I access the ‘calendartasks’ in my rss template ? There I can only use
{{ states(‘some var’) }}

Variables ?
Helpers ?

Below the notification automation:

alias: School Calender notify
description: ""
trigger:
  - platform: time_pattern
    hours: "16"
condition: []
action:
  - service: calendar.list_events
    data:
      duration:
        hours: 168
        minutes: 0
        seconds: 0
    target:
      entity_id: calendar.smartschool_taken_en_toetsen
    response_variable: calendartasks
  - service: notify.notify
    data:
      message: >-
        Schooltaken {% for event in calendartasks.events %}   {{ event.start |
        timestamp_custom('%B %d, %Y',False,default) }} - {{ event.summary }} {% endfor %}
mode: parallel
max: 10

What’s the best way ?

Thanks in advance

How did you add the smartschool calendar to HA?
Wich integration did you use?

Hello did yopu found a solution for integration ?

The calendar documentation has examples: Calendar - Home Assistant and after the description of the API there are examples of how to pull out data from the attributes into a notification.

And this thread has another set of examples for doing it a different way: