PlayStation Now additions Borderlands 3 and Marvel's Avengers are PS4-versions only
The game's are currently available to play, however.
Just before the Easter weekend, Sony announced that Borderlands 3, Marvel's Avengers and The Long Dark would be added to the subscription service PlayStation Now in April. No formats were confirmed, but it was generally believed that it would be for both PlayStation 4 and 5 as Borderlands 3 and Marvel's Avengers have free upgrades already. But it turns out this isn't the case.
As reported by IGN, who reached out to Sony for a clarification, it turns out both of these games will only be available for PlayStation 4 with no way of upgrading them or even playing them for PlayStation 5. If you want that version, you will have to buy it, but you will be able to export your save files. You can read more on how to do that over here.
While this is somewhat surprising and disappointing, it isn't the first time Sony opted for this solution as Final Fantasy VII: Remake was released to the subscription service PlayStation Plus in March, but once again only with the PlayStation 4 version and no way to use the free PlayStation 5 upgrade.