The ttkbootstrap style is not working.
The window looks like this.

The full code is here.

This is my code:

a.py:

from tkinter import filedialog
import ttkbootstrap as ttk
from ttkbootstrap.constants import *
from b import *

root = ttk.Window()

b1 = ttk.Button(root, text="Button 1", bootstyle=SUCCESS, command=test)
b1.pack(side=LEFT, padx=5, pady=10)

b2 = ttk.Button(root, text="Button 2", bootstyle=(INFO, OUTLINE))
b2.pack(side=LEFT, padx=5, pady=10)

root.mainloop()

b.py:

import ttkbootstrap as ttk
from ttkbootstrap.constants import *

def test():
    root = ttk.Window()

    b1 = ttk.Button(root, text="Button 1", bootstyle=SUCCESS)
    b1.pack(side=LEFT, padx=5, pady=10)

    root.mainloop()

When I call test() function in a.py, the window created by b.py looks strange.
It’s still the tkinter style.

How can I fix it? I don’t like the tkinter style.