From image .png to 'skeleton' structure

I’m trying to get the ‘skeleton’ of the image I’m importing.
The problem is that I’m stuck and can’t get a line that intersects the points in question. I’m trying to solve it with the Pufferfish plugin, but I can’t find the right component.

I would like to get something like this (following photo, blue line)…Could you help me?
Thank you! (8.6 MB)
Initial photo:

Thank you Laurent!
I have a problem: am trying to install the Fennec plugin, but all I get is the icon shown in the photo. I placed the .gha file in C:\Program Files\Rhino 7\Plug-ins\Grasshopper\Components and the .ghpy files in C:\Users\gprosperi\AppData\Roaming\Grasshopper\Libraries\Fennec.
I have 7.28.23058 version installed.

Install it from Package Manager