If you purchased the Mamba Forever Edition of NBA 2K21 on PlayStation 4, you're entitled to a free Standard Edition of the game on PlayStation 5.
This copy of the game is part of the PSN code for bonus content included in the physical copy of the box. It will be required to use the same PSN ID on the PlayStation 5 that you used the code with.
At this time, though, the PlayStation 5 isn't available yet, so we can't provide download instructions for that version. Please check back later: We'll update this article when we have more info to share.