Code in these fields gets removed | Settings >> Custom code

using no plugins, i tried to add JS code and it gets sanitized every time, over the facebook group people are overcoming this by directly adding the code to the page in the builder, but that is not a good practice so i want to avoid that and use the proper way. when i’m logged in i can the the code goes through

URL https://isaaac.me

What’s the code in question?

just some chat client, the code is fine no error on it, the issue exist with code in general. for instance i added this code and the alert did not fire:


<script>alert("Hello! I am an alert box!!");</script>