tkinter toggle buttons not working

[Nu2Python]

ok deanhystad, here is my newest code that I slapped together... it is messy and I know that already. It does work, and it does tell me what the current state is of the relay and starts the window with button state ON or OFF based on the status.

from tkinter import *
from tkinter import messagebox
import requests
import time
import os
import json

ws = Tk() 
ws.title('Relay Control')
ws.geometry("600x400")
ws.configure(background='white')

on = PhotoImage(file = "frPorch_on.png")
off = PhotoImage(file = "frPorch_off.png")


shelly01  = 'http://shelly1-483fda82683f/status'
shURL = 'NOT_INIT'


shURL = shelly01
sh01 = requests.get(shURL)
x = json.loads(sh01.text)
status = x["relays"]
a = status
is_on = a[0]['ison']
print(is_on)

  
def Switch():
    global is_on

    
    if is_on:
        button.config(image = off)
        label.config(text = "Switch is Off", fg = "grey", bg='white')
        requests.post('http://shelly1-483fda82683f/relay/0/?turn=off')
        is_on = False
        
    else:
        
        button.config(image = on)
        label.config(text = "Switch is On", fg = "green", bg='white')
        requests.post('http://shelly1-483fda82683f/relay/0/?turn=on')
        is_on = True



if is_on == True:
    button = Button(ws, image = on, bg='white', bd = 0, command = Switch)
    button.pack(pady = 30)
    label = Label(ws, text = "The Switch Is On!", bg='white', fg = "green", font = ("Helvetica", 32)) 
    label.pack(pady = 20)
else:
    button = Button(ws, image = off, bg='white', bd = 0, command = Switch)
    button.pack(pady = 30)
    label = Label(ws, text = "The Switch Is Off!", bg='white', fg = "grey", font = ("Helvetica", 32)) 
    label.pack(pady = 20)


ws.mainloop()