Login to your CPanel and search for Hotlink Protection, example of an icon below and click on it
Your next page will be something like this
URLs allowed to access: These are list of URLs that you will give permission to access your files
Block direct Access: This is a list of file extensions separate with commas, anyone you add can’t be hot linked
Redirect Request: Normally, if you activate this when a user wants to hotlink a file, he will get a 403 Forbidden HTTP Error. But you can customize it to redirect to another link
When you have setup all the above to your desired, you can then protect hotlink!