Image protection?

Question

htaccess

Profile has a background

body {
background: #FFFFFF url(' https://i.pximg.net/background/img/2016/05/17/11/3... ') repeat fixed;
}

But when you click on this link that leads to the image, 403 comes out, and the image is shown in the profile itself.
How to do it ? and do not write "images can be obtained from the cache, etc."

Answer 1

The first thing that came to mind was that if the referrer did not come, then we send it (not an image, but fuck it)