Hello,
Please forgive my ignorance in advance, I'm completely new to JIRA and Groovy expressions, having come from a front-end and PHP background... would really appreciate any assistance or pointers.
Goal:
Create a POST-function that will automatically set the time and date of a custom field "Quote Status Updated On (Date Time Picker)", based on whether or not the custom field "Quote Status (Select List (Single choice) )" has changed.
Attempt:
I tried creating a new field "Previous Quote Status (Select List (Single choice) )" that will copy the last value of "Quote Status", with the intention of comparing the two, and updating "Quote Status Updated On" with the current Date Time if there has been a change.
1. Copy Value From Field to Field (JMWE add-on)

Unfortunately the above does not successfully copy the value as needed, giving the following error on the view issue page:

2. Set Field Value to constant or Groovy expression (JMWE add-on) Function for this transition

The above obviously does not work since step 1 is does not copy the value, but I wonder if the syntax is correct?
If anybody has any resources, like a list of commands or expressions that are useful it would be a lifesaver, as the documentation I have does not seem comprehensive.
Thank you in advance!!