A:Answer If you buy the game physically for the ps5, you'll already have the game on ps5 and won't be eligible to have the ps4 version.
If you buy the game digitally on psn, you'll have rights to both the ps4 and ps5 version.
If you buy the game physically for the ps4, then you'll be eligible to the ps5 free upgrade. So you should be able to play the ps4 version, using your ps4 disc, as well as the ps5 version while using the ps4 disc. So if you plan on playing on both Ps4 and Ps5, I recommend buying the ps4 version physically. Or just buy the ps5 version and only play on ps5.
I hope this answers your question.
