I am using tb.Lable from ttkbootstarp but i am not able use height, bd attribute

The error ->
File “C:Program FilesPython311Libtkinter_init_.py”, line 1692, in _configure
self.tk.call(_flatten((self._w, cmd)) + self._options(cnf))
_tkinter.TclError: unknown option “-height”

This is my code ->

from tkinter import *
import ttkbootstrap as tb

class Root(tb.Window):
    def __init__(self):
        super().__init__(themename='superhero')

        self.frame = Frame(self.canvas)
        self.frame.grid(row=0, column=0, sticky="nsew")



class Slot(tb.Label):
    SlotList = [] # stores the slots objects

    def __init__(self, master=None):
        super().__init__(master)
        Slot.SlotList.append(self)
        self.config(width=40, height=20, bd=1, relief="solid", bg="white")
        self.grid(padx=30, pady=30)

if __name__ == '__main__':
    App = Root()
    App.mainloop()
`

I have tried too much to debug it but it is not working, the problem might be with tb.Lable as i remove tb. it is working properly but i want to use it with tb.Lable