New ITIL Explained for Certified Professionals | ITIL (Version 5)
The confusion usually stems from the timeline of ITIL releases. Here is the actual progression: itil v5 pdf
Since 2021, PeopleCert owns the ITIL brand. They sell official ITIL 4 publications as eBooks (PDF) and printed books. You cannot get a free full PDF, but you can purchase: New ITIL Explained for Certified Professionals | ITIL
New ITIL Explained for Certified Professionals | ITIL (Version 5) itil v5 pdf