"Approved By" Name Stamp Automation

Hello, 

I have set up an approval process within our CRM and part of the process is putting an "approved by" name on the request automatically when a user hits the "approved" button. 

The way I have this set up is an automation that puts the "last modified by" name in the approved by field. 

The issue I'm running into is it changes ALL records to that person instead of the individual record they are approving. 

I have put a date filter on this but the issue will still occur if there are multiple records with the same date.  

Is there a different way to accomplish this?

------------------------------
Jessica Stevens
------------------------------