THE MOST DIFICULT ANSWER I EVER HAD!

Question

How can I make a logout button appear using PHP after session is iniciated on my website in my current index.html? I already have a full website and login and register forms working. The code is here:
https://code.sololearn.com/WSclLB8xtwO4/?ref=app I just need the code and where to put if someone could do it. I would appreciate that a LOT!

Answer 1

But I need a live explanation through code or a video to really understand what to do.