Как обратиться к переменной в функции класса?

class App(threading.Thread):

    def __init__(self):
        threading.Thread.__init__(self)
        self.start()

    def callback(self):
        self.root.quit()

    def run(self):
        self.root = Tk()
        self.root.protocol("WM_DELETE_WINDOW", self.callback)
        self.root.geometry("1600x900")


        self.LBL_ozon = Label(text = parse(), font = "Calibri 100")
        self.LBL_ozon.place(x=100,y=100)

        self.BTN_confirm_bet = Button(text = "✔", font = "arial 20")
        self.BTN_confirm_bet.place(x=400,y=300)

        self.ENT_bet = Entry()
        self.ENT_bet.place(x=130,y=300)

        self.root.mainloop()

app = App()
def refresh_LBL_ozon():
    while True:
        App().LBL_ozon.config(text = parse())
refreshthread = threading.Thread(target = refresh_LBL_ozon)
refreshthread.start()

Ошибка:

Exception in thread Thread-2: Traceback (most recent call last): File "C:\Users\VandenMiner\AppData\Local\Programs\Python\Python38-32\lib\threading.py", line 932, in _bootstrap_inner self.run() File "C:\Users\VandenMiner\AppData\Local\Programs\Python\Python38-32\lib\threading.py", line 870, in run self._target(*self._args, **self._kwargs) File "C:\Users\VandenMiner\Desktop\Python\InvestCheker\WithTK\main.py", line 79, in refresh_LBL_ozon app.LBL_ozon.config(text = parse()) AttributeError: 'App' object has no attribute 'LBL_ozon'