I am not the author of this article but I really apologize if this article has bad practices. I am just a beginner who wants to learn how to design secure login

I am not the author of this article but I really apologize if this article has bad practices. I am just a beginner who wants to learn how to design secure login systems in Php. It's a key skill for every web developers. Please, can anyone post useful resources on designing flawless login systems in Php. Thank you.