Kamma is often translated as action.
It has a different meaning outside which finds its way in but the Pāḷi word translates as action. And action is intentional, it is not a mere motion.
'Cetanāhaṃ, bhikkhave, kammaṃ vadāmi. Cetayitvā kammaṃ karoti kāyena vācāya manasā.'
'Herewith the intention, almsmen, the action I say. Intending the action, one does by body, by speech, by intellect'. (AN 6.63)
We can only do something just now and of course, what we do leads to result; we do something precisely because of an expected result. That the exact 'result', the ripening of an action, is not found out is one thing — it is something which should not be considered (AN 4.77) — but that there is ripening that is to be understood. Action is not a matter of believing.
Do yourself a favour and don’t use kamma but use action instead so that a misunderstanding is more easily spotted by and for yourself.
Pāḷi-English
Kamma (nt.) action.