First of all, this is a forum, not a live chat. It’s not uncommon to have to wait for a few hours to get a response. No need to bump your post ever few minutes.
As for your issue itself, you were already given the answer:
You MUST add the domain to your hosting account first or you’ll get exactly this.
Pointing it to the IP address of your hosting account is not enough, because every IP address hosts many thousands of accounts. So you need to add the domain name on our end so the server knows which website to load for the domain.