在flask中使用工厂模式时，如何在flask扩展中使用配置？

from flask import Config

class MyConfig(Config):
    DEBUG = False
    SECRET_KEY = 'mysecretkey'
    DATABASE_URI = 'mysql://user:password@localhost/db_name'

from flask import Flask
from myextension import MyExtension

def create_app():
    app = Flask(__name__)
    app.config.from_object('myapp.config.MyConfig')
    
    my_extension = MyExtension(app)
    
    return app

from flask import current_app

class MyExtension:
    def __init__(self, app=None):
        if app is not None:
            self.init_app(app)
    
    def init_app(self, app):
        self.app = app
        
        # 使用配置变量
        debug_mode = app.config['DEBUG']
        secret_key = app.config['SECRET_KEY']
        database_uri = app.config['DATABASE_URI']
        
        # 其他扩展初始化操作