This article explains differences between A02, B01 and 2GB: Nvidia Jetson Nano Developer Kit A02 vs B01 vs 2GB – Tutorials of Cytron Technologies. Just look at your board and compare with the following photos:
If you have two camera slots, then you have Jetson Nano B01.
I use tegra210-p3448-0000-p3449-0000-b00.dtb, but it does not mean I have a special B00 board. I have a normal B01 board. DTB file can have any name, in my case it was its default name. Whatever a given DTB will be compatible with particular board(s), depends on its content, not its name.