Trail in three.js

I’m trying to create a stroke with the mouse, but I don’t know what is the problem.

Can you please explain in more detail what your code is supposed to do? Is an effect like the following at Shadertoy already sufficient?

https://www.shadertoy.com/view/wdXXz4

You have to hold the left mouse button down and then move it on the canvas to see the effect.

trail Im trying to make this