Trying to make game able to be restarted

Question

I am making a typing test for a project using tkinter, and the last thing I need to do is to have it be able to restart when the user presses the restart button.

  def test():
    def checksen():
      #stuff

    def stopgame():
     #stuff
      
    #main test program stuff
      while elapsed < max_time:
        #config stuff
  
        while checksen() == False:
          #stuff
       #stuff

          #after game
      correct_counter-=1#typed sentence after max time does not count
  
      senframe.destroy()
  
      endframe = tk.Frame(win, bg = norm)
      endframe.place(relx=.5,rely=0.025, anchor='n')
      
      endlabel=tk.Label(endframe, text = f'FINISH \n You typed {correct_counter} sentences in {max_time} seconds, \n which is about {round(correct_counter/max_time, 2)} sentences per second. \n Want to test again?', font = 14, bg = norm)
      endlabel.pack()
  
      restartbutton = tk.Button(endframe, text = 'RESTART', bd = 3, command = start)
      restartbutton.pack()
  
      endbutton=tk.Button(endframe, text = 'FINISH', bd = 3, command = stopgame)
      endbutton.pack()

  #stuff```

I'm trying to have it so the restart button calls on start function again, but when it's pressed, nothing happens. I'm new to programming and I'm trying to understand inner functions. Is there an easier way to make my program restart able?