from flask_sqlalchemy import SQLAlchemy

from flask_migrate import Migrate, migrate

def create_app(register_all=True, **kwargs):
    #Add this code under this method, add the database package and initialize,
     db=SQLAlchemy()
     db.init_app(app)
     #Import and initialize
    migrate=Migrate(db=db)
    migrate.init_app(app)
    return app

directory = current_ app.extensions[‘migrate’].directory

This sentence means that migrations are not generated

So you need to add migrate and initialize

DB needs to be added for initialization