Hi,
I can't find API name for field in custom object.
I was trying with below one but with no results

filter="{column:'Custom object name.CustomObjectFieldName',     or   filter="{column:'CustomObjectFieldName',  

How to get the JSON API field name (as I read it shoud be this one) for any object field?
Was trying to get this by entering adress:
eu2.salesforce.com/services/data/v35.0/analytics/reports/"reportName"/describe

but I can't download the file.

Any help?

Best
Kris