Ebooks security features: making non downloadable from website (PHP website)

We have a website https://ssccglpinnacle.com/ We develop content like ebooks along with some of our other products. We want that nobody is able to download ebooks from our website and want security features on ebooks. The website is in core PHP. https://ssccglpinnacle.com/student/pdfjs/web/viewer.php?file=English-medium-200-Essays-T3-T2-1-merged-compressed.pdf