A small Oracle APEX 23.2 app using a password as first, and TOTP as a second authenticaton factor. It also has functionality for self-registration, to handle forgotten or expired passwords, or "lost" QR-Codes/phones. I created this app just for fun. Its is certainly not intended as a "best practice" or preferred way of doing it, it is more that I saw so many other implementations doing stuff in such a way from which I thought "I would do it different". So this application is just "my way".
Please note that this application is only about authentication, there's NO AUTHORIZATION used in this DEMO application. You don't want to use this unchanged in a production environment.