QR based Encrypted Authentication System Requirement - PHP/Flutter -- 2

In urgent need of a QR-based authentication system. 1) Flutter app that takes one-time user registration/updates it to the database and then acts as a QR Scanner 2) Web app which is connected to the same database and used for Login 3) Login Verification with QR that is generated through AES or any other base of encryption code 4) Flutter app's QR scanner has the decryption code which validates the login info with the database This is the product outline. For detailed information on the product ping me. The time constraint is I need it done in less than 5 days.