from tkinter import *
import socket
from threading import Thread

def host():
    sock = socket.socket()
    sock.connect(('localhost', 9090))
    sock.send("change".encode())
    sock.close()

window = Tk()

def handle_click(event):
    th = Thread(target=host)
    th.start()

window.geometry("300x300")
window.columnconfigure(1, weight=1, minsize=75)
window.rowconfigure(1, weight=1, minsize=50)

frm = Frame(master=window, relief=RAISED, borderwidth=5)
frm.grid(row=1, column=1)
btn = Button(master=frm, text="Change", background="#28AFEA")
btn.grid(row=1, column=1)

btn.bind("<Button-1>", handle_click)

window.mainloop()