Intent as optional field in nlu.json

Hey guys, I’m trying to create an nlu.json file without define the “intent” field, only entities.

The documentation NLU Training Data says that intent is an optional field:

The intent is the intent that should be associated with the text [optional]

so it should work - however , i’ve tried that in multiple ways (with empty field, none, null) but none of them work.

Any ideas how to solve that ? Many thanks