Flask app bug fixing.

Im building a flask app to create a Back Office for my company. I'm using python, javascript, sqlalchemy. I'm having some trouble with security when deploying it to web and looking for someone with experience to guide me through and have some feeback about my choices. It is a very simple website (4 pages - login, logout, change password and a page to display each "client's info"). What do you think about this? Can you help me? :) Please kindly confirm the value for this service.