Question about ASUS PRIME B450M-K II

The Bios version is not on the packaging and can therefore only be checked after installation. So nobody will be able to tell you that.
However, the motherboard has a "Bios Flashback" button, which can be used to upgrade the Bios without a "working" CPU.
See the Asus manual.

Sorry I can't give you any information because I don't know anymore, I always do a BIOS update to the latest release BIOS first