Date histogram and JSON imput

Hi, I am on Kibana 7.2. I would like to show the average of some field for the last 24 months, but when I put this image. It aggregate on 730 days and show the average of it. But I want the avarege individually per month for the last 24 months. Could I do it on the field JSON imput? And I would more docs about this field.

You should change the interval to 1M and then in the timpicker (top right) select "Last 24 months". This way you can see the average individually per month, for the last 24 months.