I have this test on selenium Python:

import pytest
from selenium import webdriver
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from pages.main_page import MainPage

def test_click_account(main_page):
    main_page.click_account()

“main_page.click_account()” is executing this def from my main_page:

import time
from selenium.webdriver.common.by import By
from .base_page import BasePage

class MainPage(BasePage):
     
    def click_account(self):
        ACCOUNT_LINK = (By.XPATH, "//li[3]/a/span")
        self.assert_boton_visible()
        self.click(ACCOUNT_LINK)

“self.assert_boton_visible()” is executing this code from my main_page:

import time
from selenium.webdriver.support.ui import WebDriverWait, Select
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver import ActionChains

class BasePage:

    def assert_boton_visible(self):
        element = self.find_element("xpath", "//li[3]/a/span")
        assert element.is_displayed()

When executing the test, I receive this error: AttributeError: ‘MainPage’ object has no attribute ‘find_element’

What Im doing wrong? Im triying to do an assert checking if the element with that xpath is displayed or not