Bluefield-2 ES platform software

Mellanox BlueField-2 A1 BL1 V1.1
ERROR: Failed to load BL2R firmware.

https://docs.nvidia.com/networking/display/BlueFieldDPUOSLatest/Supported+Platforms+and+Interoperability
it says it have development keys. but it don’t provide the firmware…
how to get.