Rockey Linux 8.8 and BOSS-1 - can't detect drive?

I have a PowerEdge R640, BIOS ver. 2.18.1, iDRAC 5 (firmware version 5.10.50.00 build 32), and a BOSS-S1 card in PCI slot 2 with a 480MB Intel M.2 SATA drive as recommended in "Dell Boot Optimized Storage Solution-S1
User's Guide". I also have a RAID-5 of 8 SAS disks.

I can boot up into Rocky Linux 8.8 (this is a clone of RedHat 8) from USB, and it detects the raid array, but not the drive on the BOSS card; since BOSS means Boot Optimized Storage Solution, this is where I want my OS to be - there must be a way to make it visible to the installer.

How do I solve this problem?