Pendulum with trajectory display with paint

Hi, in this gif you hace a real trajectory off pendulum. My aim is to obtain trajectory like this video, to make a drawing by keeping differents points with all the race off the pendulum.
https://i.imgur.com/vOQgFMe.gif
At time, the script obtain a plane trajectory not 3D trajectory.
It is difficult to obtain the drawing, thanks in advance.
Spectrum.

the source of code is working fine on a plan not 3D trajectory.
https://gamedev.stackexchange.com/questions/75673/unity-falling-body-pendulum-behaviour/75748#75748