The hotlink protection tool blocks other websites and visitors from directly linking to files and pictures on your website.
To start protecting your website's resources, just head over to your hosting account's hPanel and locate the Hotlink Protection menu. In the Configure Hotlink Protection section, you can configure your website's resources protection. You can block either all access to your website's resources or only specific file types (videos, images, downloads and etc.).
You can also deny direct access (this is great if you do not wish for your visitors to link your images specifically, instead they would be forced to share the whole page and not just the image).
Using the Redirect blocked requests to this URL field, you can redirect all of the visitors trying to access your resources to a specific page, for example, an error page.
Make sure that your hotlink protection status is set to Enabled.
Feel free to check this tutorial for more information on configuring the hotlink protection :)