PHB physical and digital

I have the physical copy of the PHB and some other books that I bought a while ago. I was wondering if there is a way for me to get them on dnd beyond as well or would I have to buy  them again.

You would have to buy them again.*

* If you just need some parts, you can buy them piecemeal as you need them, and that money spent reduces the price of the PHB.

Also, if you're in a campaign, somebody else often has the books and turns on sharing, so you don't need the book to build a character in a campaign.