Creating a new coordinate system

Thanks @mau_igna_06
I am afraid I am not sure I know how to.
Is there a basic tutorial on the steps to run a script like this?
I don’t want to waste your time as I have no experience at all in any scripting/coding so maybe I need to start somewhere else?

I tried to copy and paste these 2 lines in the python interactor using an empty Slicer scene, press enter and obtained a few error lines:

PlaneNode = getNode(‘P’)
Traceback (most recent call last):
File “”, line 1, in
File “/Applications/Slicer.app/Contents/bin/Python/slicer/util.py”, line 1312, in getNode
raise MRMLNodeNotFoundException(“could not find nodes in the scene by name or id ‘%s’” % (pattern if (isinstance(pattern, str)) else “”))
slicer.util.MRMLNodeNotFoundException: could not find nodes in the scene by name or id ‘P’
PlaneNode.SetPlaneType(PlaneNode.PlaneTypePlaneFit)
Traceback (most recent call last):
File “”, line 1, in
NameError: name ‘PlaneNode’ is not defined

I suspect I need a plane object in my scene maybe, which should be named P? Or is the P node the Fiducial list which is F by default in my 3D Slicer version? Do I need 3 points in the scene before I run the code or after? Will the plane appear as I place the 3 points? Is there any other prerequisite in the the scene before the script is run? Like a 3D object or a CT study?
Very sorry if these questions are extremely basic. I completely understand if this scripting module is meant for people with basic programming skills and maybe I should stick to the modules already created.
Guillaume