Run external script if a specific calendar is modified

I’m looking for a way to run an external script whenever a specific calendar is modified (without polling). What would be the best approach to accomplish this?

Is there e.g. a better way (for someone that is new to Nextcloud app development) than taking the “workflow_script” app as an example and listen to the OCP event dispatcher and filter for CalendarObject… events?

That is actually the best way.