Unable to Access Registered Class Properties (Properties Grouped in Class)

Question

I'm grouping my properties in a class
like this:

class CTL_test(bpy.types.PropertyGroup):
    variable = bpy.props.StringProperty(name='Variable', description='', default='', subtype='NONE', maxlen=0)

bpy.utils.register_class(CTL_test)
bpy.types.Scene.ctl_test = bpy.props.PointerProperty(type=CTL_test)

After that if I access bpy.context.scene.ctl_test.variable,
This will give:

And, if I try to access, Scene.ctl_test.bl_rna.properties['variable']

AttributeError: 'CTL_test' object has no attribute 'variable'

Same, When I use this property in Interface, Like -

row_5.prop(bpy.context.scene.ctl_test, 'variable', text='Name', icon_value=0, emboss=True)

This will give Error:

property not found: CTL_test.variable

Where I'm wrong?

Answer 1

The Problem is Solved,

class ClassName(bpy.types.PropertyGroup):
    # Normal Data in Python Class
    label = 'My CTL Group'

    # Blender DataProperty in Python Class
    new_property: bpy.props.StringProperty(name='New Property')

And,

This Output Shows that bpy.types.Scene.new_property has registered successfully,
But class has not registered.

When, Both registers successfully, the output will look like this (default value)