Played on ps4, now it wants me to buy again on ps5 for either

PS4 error codes and how to fix them

Is this only playable on ps5 or also ps4? It says 'only playable on ps5' but the title says Ps4 and Ps5. I have a ps4 and I need to know this

Choosing the Right PlayStation 5

PS5 review: an exciting portal to next-gen gameplay

How to control your PS4 from your PS5

Sony PlayStation 5 (PS5) Video Game Console

PS5 stock updates UK: Latest restock news from Game, John Lewis, Smyths, Argos and more

PS5 stock: latest updates on where to buy the PlayStation 5

Play your PS5 console over your home Wi-Fi with console-quality controls using the PlayStation Portal Remote Player. Experience the incredible immersion of the DualSense wireless controller with features like haptic feedback and adaptive triggers in supported games. Put your game collection on PS5 in the palm of your hand with the PlayStation Portal Remote Player, which can play compatible games you have installed on your console without needing to play on a TV.