Transform (Group By) and Change Field Name


I want to use bar chart to show the number of alarm which I have.
I am able to group these alarms based on the origin of the alarm by using Group by > Distinct Count.
But the problem occurs when I tried to visualize the data by using the bar chart, it takes the name of my column (message(distinctcount) instead of the grouped parameter (origin). Is there any way to change this?