Hi @Joachim_,
Do you want to filter the eligible event and then get its event Id and then configure it in Delete event action?
Your method seems to be valid in my opinion, but the Id configured in "Delete event" action should not be "Current item". The "Current item" contains not only the event Id, but also other information about the event. .
You should use the expression "items('Iterate_through_deleted_events')['Id']" to get the event id:
items('Iterate_through_deleted_events')['Id']

What is filled in the specific "items()" depends on the name of your action. If there is a space, you need to replace the space with "_".
Please take a try.
Best Regards,
Barry