Save dates Service Request when status change

Good afternoon !

How can I save dates in a ServiceRequest when the status change?
For example I have a ServiceRequest with status “ACTIVE” and its occurrenceDateTime is 2019-08-25. I would like change status to “COMPLETED”. Where can I save this date ?

A new Provenance instance should be created every time the ServiceRequest changes. You can see the dates for each change there.

I don’t know what is this resource. I will search about it for to see how it can help me.