Support the publisher by purchasing the official digital edition. If you seek the texts within it: Download legal, public-domain translations of Enoch, Jasher, Jubilees, and the Apocrypha from academic sources. If you seek a standard Bible: Use the NRSV, ESV, or KJV, which are available as free, legal PDFs through Bible websites and apps.
Ultimately, the Cepher is best understood not as “the original Bible” (as its promoters sometimes claim) but as a modern, sectarian compilation with a very specific theological agenda. Whether that agenda aligns with your own faith or research interests will determine if the search for its PDF is a journey worth taking.