All beginnings are difficult - sum of customfield value


i have a problem with create new column in my report. In my first column I added only isue in status closed. In my second column i would like add sum of customfiled value (“Ocena z badania”) only for issue in status closed.
I imported data from the field during import and i see in my Measures section Custom FIled, but “Ocena z badania closed” does not display any results.

Best regards