Getting a DISTINCT count in Access Intelligence Center

I am trying to create a line chart showing how many different people are creating access requests each month. This would be a nice way to show management how users are adopting ISC.

I have created a line chart in AIC Audit using CREATED.autoCalendar.YearMonth for the dimension and Count(ACTOR_NAME) as the measurement. This is only showing me how many access requests were submitted. Is there a way to get a COUNT(DISTINCT(ACTOR_NAME))?

Well, there is nothing like posting a question that will magically cause the answer to present itself. After a little clicking around I found the answer.
Turn on the Advanced options
Click the chart
Click on Measures
There, you can edit the expression.

Awesome that you also posted the solution! Kudos!

Can you share a screenshot showing where exactly is this Advanced options visible in UI?

Sure thing.