Resolved: how to stop tkinter timer function when i press button one more times?

    root.after_cancel(AFTER) 
AFTER = None
def countdown(count,time,name):
    global AFTER
    time['text'] =name,":",datetime.fromtimestamp(count).strftime("%M:%S")
    if count > 0 :
        AFTER = root.after(1000, countdown, count-1,time,name)
    elif count == 0 :
        time['text'] = f"Возрожден:{name}"```

def countdown():
    global countdownValue
    if countdownValue > 0 :
        print(' countdown: ', countdownValue)
        countdownValue -= 1
    if countdownValue == 0 :
        countdownValue = -1
        print(f"\n  Возрожден:  {name} :) ")
    root.after(1000, countdown)

def startStopCountdown():
    global countdownValue
    if countdownValue > 0:
        print('stopCountdown')
        countdownValue = -1
    else: 
        print('startCountdown')
        countdownValue = 10

import tkinter as tk
countdownValue = -1
name           = 'Возро'
    
root = tk.Tk()
root.title("3,2,1,...")
btn = tk.Button( root, text="Countdown", font=('',20), 
                 command=startStopCountdown)
btn.grid()
countdown()
root.mainloop()