how to remove the background of a Label in tkinter python code example

Example: how to remove the background on text in tkinter python

from tkinter import *
from tkinter import messagebox
import tkinter
import hashlib
from PIL import Image, ImageTk
from win32api import GetSystemMetrics

#===========================================================================================
#functions to center windows
def center_window_x(width):
    x_coordinate = (GetSystemMetrics(0)/2) - (width/2)
    return x_coordinate
def center_window_y(height):
    y_coordinate = (GetSystemMetrics(1)/2) - (height/2)
    return y_coordinate


#===========================================================================================
#function to create setup page
def first_time_setup(width, height):
    setup_window = Tk()

    #===========================================================================================
    #remove window border and position in center
    setup_window.overrideredirect(1)
    setup_frame = Frame(setup_window)
    setup_frame.pack_propagate(False)
    setup_window.geometry('%dx%d+%d+%d' % (width, height, center_window_x(width), center_window_y(height)))

    #===========================================================================================
    #background image for setup window
    canvas = Canvas(setup_window, width=width, height=height)
    canvas.grid(columnspan=2)
    image = Image.open("setup_background.jpg")
    canvas.image = ImageTk.PhotoImage(image)
    canvas.create_image(0, 0, image=canvas.image, anchor="nw")

    #===================================================================================================
    #add username label
    start_title = Label(setup_window, text="Username")
    start_title.place(x=430,y=225)

    #===================================================================================================
    #add admin user entry box 
    admin_user_ent = Entry(setup_window)
    admin_user_ent.place(x=500,y=225)

first_time_setup(650, 300)