How to limit access to website during development
If you would like to limit access to your website during its development, so that only you and your developer can access it, there are several ways to do that.
Use a maintenance plugin
There are plugins for web applications that provide maintenance functionality. Depending on the plugin used the maintenance functionality may be different, but usually visitors to your website see a "coming soon" page or a page that shows a timer how much is left until the website is publicly accessible. Using plugins allows you to customize the maintenance pages, so you can develop them to match the look on your website. You can find such plugins in the official extension repository of the website's application, for example:
Password protect the website
Using cPanel's Password Protected Directories tool you can add a password protection on your website. This will make the website only accessible to people who know the credentials for accessing it. More information on how to use the tool can be found here.
Block all access and allow only your IP
To use this method you should open the .htaccess file for your website and inside it, place the following lines at the top:
deny from all
allow from IP.IP.IP.IP