I am unable to help function without beer? (7)

I believe the answer is:

nocando

I'm a little stuck... Click here to teach me more about this clue!

'i am unable to help function' is the definition.
I know nothing about this answer so I can't judge whether this works.

'without beer?' is the wordplay.
'without' becomes 'no'.
'beer?' becomes 'cando' (I am not sure about this - if you are sure you should believe this answer much more).
'no'+'cando'='NOCANDO'

Can you help me to learn more?

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app