text: from flask import Flask   
  from config import config_options
  from flask_bootstrap import Bootstrap
  from flask_sqlalchemy import SQLAlchemy
  from flask_login import LoginManager
  from flask_mail import Mail
  
  #........
  mail = Mail()
  
  def create_app(config_name):
      app = Flask(__name__)
      #........
      mail.init_app(app)
  login_manager = LoginManager()
  login_manager.session_protection = 'strong'
  login_manager.login_view = 'auth.login'
  
  bootstrap = Bootstrap()
  db = SQLAlchemy() 
  
  def create_app(config_name):   
      # initializing application  
      app = Flask(__name__)
      # setting up configuration    
      app.config.from_object(config_options[config_name])
  
      # Initializing flask extensions  
      bootstrap.init_app(app)  
      db.init_app(app)     
      login_manager.init_app(app)
      # Registering the blueprint
      from .main import main as main_blueprint
      app.register_blueprint(main_blueprint)
      from .auth import auth as auth_blueprint
      app.register_blueprint(auth_blueprint, url_prefix='/authenticate')
  
      # Setting config
  
      return app
  