I don't run RAID so I don't have much experience. But the Manual states Raid should be obtainable using M.2_3 and M.2_4. The board has all sorts of restrictions on which slots can be used together and what it effects in other areas. And with a 10th Gen processor, it gets even more complicated.
But lets say you had 2 M.2 NVMe drives in those slots. First the manual also seems to say, only M.2_4 will do SATA mode. When you want an NVMe drive to function as SATA you need to install the F6 Floppy drivers during the initial install.
If you open the Bios and select EZ Bios, do you see an Intel RAID option in the lower left middle of the window? Is that enabled?
Maximus Z790 Hero,
Intel i9-13900k
Intel BE200