The book suggests you should print the sigils onto black cardstock using a silver or white ink printer. Digital screens emit light (solar), which disrupts the chthonic (dark) energy. Use an e-ink tablet or printed pages.
If you insist on the aesthetic of the original but lack cash, request the book via Inter-Library Loan (ILL) at your local library. Yes, public libraries can get obscure occult books. Once you have the physical copy for 3 weeks, you can scan your own personal worksheets (fair use for study). This is tedious but effective. liber khthonia pdf work
The Liber Khthonia PDF is not without its critics and dangers. Title: The Black Earth Ascending: A Detailed Analysis