How to use combobox-2

combobox_2.py

import ctypes
import tkinter
from tkinter import ttk


def get_selected():
    b["text"] = combobox.get()


if __name__ == "__main__":
    ctypes.windll.shcore.SetProcessDpiAwareness(1)

    root = tkinter.Tk()

    #button
    b = tkinter.Button(
        root,
        text = "selected",
        width = 15,
        bg = "lightblue",
        command = get_selected,
    )
    b.pack()

    #combobox
    item_list = ["Easy", "Normal", "Hard"]
    combobox = ttk.Combobox(
        root,
        values = item_list, #set initial value
    )
    combobox.pack()
    
    root.mainloop()