Among threading, concurrency, and parallelism, what's the best concept to use in counter gui(tkinter)?

from tkinter import *

window = Tk()
window.geometry('300x100')
window.title('Counter')
window.resizable(0, 0)

counter = -1
running = False


def counter_label(lbl):
    def count():
        if running:
            global counter
            if counter == -1:
                display = "0"
            else:
                display = str(counter)

            lbl['text'] = display

            lbl.after(1000, count)
            counter += 1

    count()


def StartTimer(lbl):
    global running
    running = True
    counter_label(lbl)
    start_btn['state'] = 'disabled'
    stop_btn['state'] = 'normal'


def StopTimer():
    global running
    start_btn['state'] = 'normal'
    stop_btn['state'] = 'disabled'
    running = False


lbl = Label(window, text="0", width=8)
lbl.grid(column=4, row=2)
lbl.place(x=170, y=15)
label_msg = Label(window, text="Counter")
label_msg.place(x=100, y=15)

start_btn = Button(window, text='Start Counting', width=16, command=lambda: StartTimer(lbl))
start_btn.grid(column=2, row=3)

stop_btn = Button(window, text='Stop Counting', width=16, state='disabled', command=StopTimer)
stop_btn.grid(column=5, row=3)


start_btn.place(x=25, y=40)
stop_btn.place(x=155, y=40)


window.mainloop()