Before using a domain with your hosting account, it has to point to the appropriate nameservers :)
To find out which nameservers your domain should point to, simply locate the Details menu in your hosting account's hPanel's section Accounts and check the Nameserver Details section.
You can also check your current nameservers by locating the Domains section at the top of the selection bar in your account's Members Area.
Hostinger nameserver details:
- Your domain's nameservers can only be set from your Domain Name Registrars side. Notice that some registrars allow their domains to be pointed ONLY via A Record. You can check this tutorial to guide you through the process.
- Changes to your domain's nameservers will need 24-48 hours to fully propagate worldwide. Your website may experience issues during this period.