how to use progressbar (indeterminate)

progressbar_indeterminate.py

import ctypes
import tkinter
from tkinter import ttk

#button function
def start_progressbar():
    if cb["text"] == "start":
        pb.start(interval=10)
        cb["text"] = "stop"
    else:
        pb.stop()
        cb["text"] = "start"


if __name__ == "__main__":
    ctypes.windll.shcore.SetProcessDpiAwareness(1)
    
    root = tkinter.Tk()

    #variable for counter
    var = tkinter.IntVar(root)  

    #Progressbar(indeterminate)
    pb = ttk.Progressbar(
        root,
        mode="indeterminate",   #indeterminate mode
        orient="horizontal",    #orient
        )
    pb.pack()

    #countup button
    cb = tkinter.Button(
        root,
        text="start",
        command=start_progressbar,
    )
    cb.pack()

    root.mainloop()