Creating an object in js lost all built-in function links

When is js I create a new Object : 
new MyObject(); which extends Sprite2D, the object is well created, but the functions _process, _ready, _draw and all the built-in functions are not called.
It seems to only happen when I try to create an object which is not initially linked to the scene. I mean, I didn't put the script on an object on my scene in the editor.
I am using Godot 4.0.