https://www.sourceguardian.com/online-php-encoder.html

https://codewithawa.com/posts/user-account-management,-roles,-permissions,-authentication-php-and-mysql---part-3


https://www.geeksforgeeks.org/dynamically-generating-a-qr-code-using-php/



https://www.inettutor.com/programming-tutorial/php/qr-code-generator-in-php-free-source-code-and-tutorial/