Delete old processes and due task


Good morning.
I’m trying to delete old processes by specifying a specific date with Rest API. I would also like to eliminate expired tasks. I have tried with the following REST operations:

POST /process-instance/delete
DELETE /process-instance

POST process-instance/delete
DELETE /process-definition

This one gives me the following error:

“type”: “ProcessEngineException”,
“message”: “Unknown property used in expression: #{(variable)}. Cause: Cannot resolve identifier ‘variable’”

I hope you could help me.