PHP Build a Basic PHP Website (2018) Enhancing a Form Escaping Output

I wanted to test what happend if i dont escape the input but the code im pasting into the input does'nt do anything

Hi. i wanted to see what exactly xss looks like. so instead of using htmlspecialchars() i just pasted this code into the input:

<script>alert("hi");</script>

and i pressed submit and nothing happend

why is it not working?

snapshot: https://w.trhou.se/v3tg48lhbh