How to find empty values in a kibana query

I'm getting the logs with statusCode 200 and empty statuscodes , I need to find the logs with empty statuscode

I've tried using statusCode:" " but it didn't worked

Hint: The statuscode for success can be written as statusCode:200

What about NOT statusCode:*?

No ,its not working

It depends what "empty" means in your case. Empty string? A string with a space? Undefined? 0? Check how your documents actually look like, that should help building the query