Hi @Anonymous
Based on your scenario, the flow has to be scheduled daily i assume. Follow the below steps
1. Create a flow of 'Scheduled-from blank'. Give it a name and choose the schedule
2. Add 'Get Items' action and select the appropriate properties. In the advanced option, for 'Filter Query' use the value EndDate lt 'utcNow()'. I have used the default 'EndDate' field for checking the expiry.
3. Add an action named 'Apply to each'. Give the value as body('Get_Items')?['value']
4. Inside the 'Apply to each' action, add 'Delete Item' action and select the appropriate properties. For the 'Id' property give the value as items('Apply_to_each')?['ID']

Thats it, all the agenda or events whose enddate is already expired will be deleted.
Hope it helps, please like it or mark it as a solution if it resolves ur clarification or issue
-Sudharsan K...