To protect a website from hotlinking, perform the following steps:
1 - Logged in to Plesk, https://your domain name:8443.
2 - Go to Websites & Domains, and locate the website's domain name.
3 - Click Hotlink Protection.
4 - Click Switch On to enable the protection from hotlinking.
5 - Specify the extensions of files that you want to protect from hotlinking (for example, jpg, bmp, and so on) in the Protected files extensions field.
6 - If you want to allow direct linking to your files from certain sites, type the website addresses into the Addresses of friendly websites field, and click Add.
7 - Click OK.
