No no, we are sure about that. We do not have any free will.
I'd not post this comment after writing it to prove my free will but it wouldn't prove it to you that way lol
As Schopenhauer put it, "it is the laws of nature that arise from a transpersonal will, not the will from the laws of nature".
A good read on the topic:
https://blogs.scientificamerican.com/observations/yes-free-w...