Is this Quentin Meillassoux's argument?

Philosophy enthusiast here.

I read After Finitude but could not understand it fully.

This is what I gather his argument is.

Q:
How do we know absolute reality exists?
E.g How do we know tennis balls actually exists?
A:
a. It's wrong to ask whether stuff exist?
b. What is more paramount is that possibilities (Contingencies ?) exist.
c. It's possible that tennis balls can get destroyed by fire etc. i.e. possibility
d. Since possibilities exist for sure (how do we know this for sure?), the things that make up those possibilities (i.e tennis balls) have to exist.
e. So stuff (tennis balls) exist.

Is this his argument??

On face-value this looks circular reasoning because one cannot think of "possibilities" without thinking about the stuff that make up those possibilities. I.e You cannot think of tennis balls getting destroyed by fire without thinking about tennis balls. So it's circular reasoning which is wrong.

Is this what Quentin Meillassoux's argument or have I got it all wrong??