If I buy physical edition of GOW:R on PS5 do I get the PS4 version as well?

I have both a PS5 and a PS4 and I was wondering if I get God of War: Ranagrock on PS5 the physical edition does the disc contain the PS4 version as well? Am I able to download the PS4 version with the disc inserted? Or is the way to get both versions to buy the PS4 version and then pay for the upgrade?I know if I get the game digitally I get access to both.

So is the best way to want to physical edition of both is basically to get the PS4 version and then pay for the PS5 upgrade?