As soon you purchase a new domain, you need to set it up. In order to do it, go to your panel homepage and click on Setup:

In the next step, you will be required to complete the domain registration by entering the domain's contact details. Make sure to use the valid data, avoiding the use of aliases instead of real names, or leaving empty fields. This will ensure that the registration is completed successfully and prevent any future issues.
As soon as you complete these steps, the activation process will start. Usually, activation is fully completed in about 2 hours or less.
If the domain doesn’t work after a few hours after registration, most likely it’s due to DNS cache. DNS records need some time for updating and might be cached with your web browser or with your Internet Service Provider. Flushing DNS Cache should help you see your domain active.
While your domain is activating, you can:
Ensure your domain has up-to-date Hostinger nameservers
Add the domain to your hosting account or park it
Start building your website using our preview domain to see the progress
Also, you will receive a message from @hostingerdomains.com to the domain's registered email address to verify it. Make sure to complete the verification process by clicking on the provided link 😊