Hi domtrump,
Welcome to the Apple Community.
Sorry I don't know a way to sync that .pdf from your Pc to your iPhone without iCloud:
Eg:
The Apple Support article: "Read PDF documents in Books on iPhone"
Says:
ie: To view .pdfs across devices, where you’re signed in with the same Apple ID.:
Go to Settings > [your name] > iCloud, turn on iCloud Drive, then turn on Books.
Then go to Settings > Books, and turn on iCloud Drive.
Complete article: https://support.apple.com/en-au/guide/iphone/iphab2193d5/ios
NB: Of course, you'd need to set up your PC to use iCloud too,
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ELSE:
One simple way may be to:
Redownload books and audiobooks
See "How to redownload books or audiobooks on an iPhone" in this Apple Support article
https://support.apple.com/en-us/HT211819
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OR
You could simply eMail the PDF to yourself from PC and open/ save it to Books on iPhone:
The article: "Read PDF documents in Books on iPhone"
Says:
In the Books app, you can open and save PDFs that you receive in Mail, Messages, and other apps.
Tap the PDF attachment to open it, tap , then tap Books
https://support.apple.com/en-au/guide/iphone/iphab2193d5/ios
Hope this helps you :-)