Text inside ttk.button is not centered

Question

I created a button using ttk.button and put text on it, but the text is not centered inside the button, I have already tried using ttk.Style() but it seems that it is not being applied, what could be happening?

from textwrap import fill
import tkinter as tk
from turtle import bgcolor, heading, width
import ttkbootstrap as ttk
from ttkbootstrap.constants import *
from PIL import Image, ImageTk


class APP:

    def __init__(self):
        # Criando a janela principal
        self.root = tk.Tk()
        self.root.title("Test")
        self.root.geometry("1080x600")  # Define o tamanho da janela
        # Impede o redimensionamento da janela
        self.root.resizable(False, False)

        # Carregando a imagem existente
        background_image = Image.open("background.png")

        # Convertendo a imagem para o formato Tkinter PhotoImage
        self.background_photo = ImageTk.PhotoImage(background_image)

        # Criando um rótulo com a imagem como plano de fundo
        self.background_label = tk.Label(
            self.root, image=self.background_photo)
        self.background_label.place(x=0, y=0, relwidth=1, relheight=1)

        style_button = ttk.Style()
        style_button.theme_use("litera")
        style_button.configure("TButton", padx=5, pady=10, anchor="w")

        # Criando o frame do Dataset
        self.dataset_frame = ttk.Frame(self.root, height=10)
        self.dataset_frame.grid(row=0, column=0, pady=10, padx=5)

        self.dataset_label = ttk.Label(
            self.dataset_frame, text="Dataset: ", bootstyle="inverse-primary", width=47)
        self.dataset_label.configure(font=("Arial", 14, "bold"))
        self.dataset_label.pack(side=LEFT, fill="x")

        self.directory_entry = ttk.Entry(
            self.dataset_frame, width=55, bootstyle="primary")
        self.directory_entry.place(
            relx=0.5, rely=0.5, relheight=0.9, anchor="center")

        self.directory_button = ttk.Button(
            self.dataset_frame, style="TButton", text="Selecionar")
        self.directory_button.place(
            relx=0.92, rely=0.5, relheight=0.8, anchor="center")

        # Criando o frame do preview
        self.preview_frame = tk.Frame(self.root)
        self.preview_frame.grid(row=0, column=1, pady=10, padx=5)

        self.preview_label = ttk.Label(
            self.preview_frame, text="Preview: ", bootstyle="inverse-primary", width=48)
        self.preview_label.configure(font=("Arial", 14, "bold"))
        self.preview_label.pack(side=LEFT, fill="both")

        # Inicia o loop principal da aplicação
        self.root.mainloop()


# Inicializa a aplicação
app = APP()

An example of how it looks, I wanted to center the text inside the button: