How to obtain a smoothing spline minima using the curve fitting toolbox.

Hi Community,

I have acquired a set of (X, Y) coordinates from a sensor reading, and used the Curve Fitting toolbox to plot its graph and produce the spline fitting my data (smoothingspline).

I was wondering if someone could indicate me ways through which I can find the resulting spline minima. I tried looking at the function fnmin as per the documentation, as it does exactly what Im trying to do, but I remain confused as to how to find it in the toolbox GUI.

Any help would be greatly appreciated. Thank You.