To support the author and ensure you receive a high-quality, malware-free file, you should source your EPUB through official channels:

The EPUB (Electronic Publication) format is the standard for most e-readers and apps like Apple Books, Google Play Books, and Kobo. Unlike PDFs, EPUB files are "reflowable," meaning the text adjusts to fit your screen size, allowing you to change fonts and text sizes for a more comfortable reading experience. How to Access the Book Legally

Check if it is currently at major library systems.