If your domain name is registered with Hostinger, please follow these steps to update your nameservers:
Login to the control panel of Hostinger
Head to Hosting -> Accounts -> Details
All DNS related information can be found in the Details section:
The list of name servers will look like this:
Use this section to add the exact nameservers we've provided
Click Update to complete your nameservers update
Your nameservers update will be processed within 3-6 hours. However, it may take up to 72 hours for it to be visible everywhere.