I am trying to add a custiom property to an add on but it shows me an error I am following this video
https://youtu.be/XqX5wh4YeRw?t=2451
i have done everything the same way but it does not seem to work
here is my code
import bpy
from math import radians
from bpy.props import *


class MyOperator(bpy.types.Operator):
    &quot;&quot;&quot;Tooltip&quot;&quot;&quot;
    bl_idname = &quot;object.my_operator&quot;
    bl_label = &quot;MyOperator&quot;
    bl_options = {'REGISTER', 'UNDO'}
    
    
    
    #create properties
    noise_scale : bpy.props.FloatProperty(
        name = &quot;Noise Scale&quot;,
        discrription = &quot;the Scale of the noise&quot;,
        default =1.0,
        min = 0.0,
        max = 2.0
        )

and it shows me this error.
'MyOperator' object has no attribute 'noise_scale'
Spelling Error
Quite likely the property fails to register because it has no idea what discrription  is. (Most likely you are alerted to this error when trying to register the operator class) Coding is about attention to detail.  Recommend for blender coding questions here, adding minimal, but runable, code to your question eg the register code for above.
Sure enough, tacking bpy.utils.register_class(MyOperator) to the question code, and checking system console
TypeError: 'discrription' is an invalid keyword argument for FloatProperty()
ValueError: bpy_struct &quot;OBJECT_OT_my_operator&quot; registration error: noise_scale could not register

any attempt to use noise_scale with this operator will lead to error as mentioned in question.
Use description instead and will register as intended.
&gt;&gt;&gt; bpy.ops.object.my_operator(
my_operator()
bpy.ops.object.my_operator(noise_scale=1)
Tooltip