Como abrir um Web Browser URL Link usando Tkinter

Para abrir site de forma automática pode tentar a seguinte maneira:

from selenium import webdriver  #pip install selenium
from selenium.webdriver.common.keys import Keys
from webdriver_manager.chrome import ChromeDriverManager #pip install webdriver_manager
import time

#Abre o Chrome
driver = webdriver.Chrome(ChromeDriverManager().install())
driver.get('https://web.whatsapp.com') #abre o site Whatsapp Web
time.sleep(15)

import tkinter
class appsite_tk(tkinter.Tk):
def __init__(self,parent):
tkinter.Tk.__init__(self,parent)
self.parent = parent
self.initialize()

def initialize(self):
self.grid()
#titulo
titulo = tkinter.Label(self, text="Abrir um Site ",
font=("Arial 14 bold"),anchor="center",
fg="Black" ,bg="blue")
titulo.grid(column=0,row=0,columnspan=2, sticky='EW')
espaco = tkinter.Label(self, text="",anchor="center",bg="snow")
espaco.grid(column=0, row=1, columnspan=2, sticky='EW')

# Variáveis Texto
site=tkinter.Label(self,text="Site: ", font=("Times 12"),
anchor="w",fg="slate gray" ,bg="cyan")
site.grid(column=0, row=2, columnspan=1, sticky='EW')
espaco1 = tkinter.Label(self, text="", anchor="center", bg="snow")
espaco1.grid(column=0, row=4, columnspan=2, sticky='EW')
# Entradas
self.st = tkinter.StringVar()
sites = tkinter.Entry(self, textvariable=self.st)
sites.grid(column=1, row=2, sticky='EW')
# Butão
butao = tkinter.Button (self, text="Abrir o Site",command=self.butaoclick)
butao.grid(column=0,row=5,columnspan=2)

self.grid_columnconfigure(0, weight=1)
self.resizable(True, True)

def butaoclick(self):
import webbrowser
new = 2
site2 = self.st.get()
url = "https://www." + site2 + "/"
webbrowser.open(url, new=new)

if __name__ == "__main__":
app = appsite_tk(None)
app.title('Abrir um site')

app.mainloop()


Exemplo: