If you define free will as a ghost in the machine then you're right. But it isn't. Treating it as it presents itself (making choices, agency, etc) defined as a simple material mental process means it's a) determined but b) meaningful. Snip it out and the resulting action doesn't happen. I blame Descartes:-)

Here's a more formal workout of the above.

https://medium.com/the-philosophers-stone/free-will-considered-as-three-lunches-v2-c4d373901551