Yes, we have free will. It is quite easily observable.

However, if you place the constrains of "Modern Materialistic Science" you cannot prove or disprove free will.
This is not an issue of free will, it is a problem of "Modern Materialistic Science". It literally defines the experience as unproveable. It even defines it as unstudiable.

"Modern Materialistic Science" separated physics from metaphysics.
And thus, you cannot use scientific analysis on the occurrence of free will.

Further, i could make an even more solid sounding case for there not being any free will.
I can show you many lives, and all the choices that that person could/would make basically work out the same. Imagine plotting a life path in 3D. each stream of light a path, each choice a divergence, splitting of paths. And when we look at most people's lives up close, it looks kinda like a log with no branches.
When we look at it further away, it looks like a straight line.

However, given this analogy, there are many people who have a log with a branch, or several branches.