Page redirects to 403 Forbidden error

I am developing a basic chat application for training purposes, I was running it on a localhost.
But now I want to test it online.
I have a problem that the page http://ahmedheikal-works.rf.gd/chattent/public/chatroom.php redirects to the 403 forbidden page.

what can cause this error and how can I fix it.

Chat rooms are blocked, which is why you see that error. We don’t allow chat scripts because they overload the servers.