Skimmed, will task to research later for more details.
1) Make sure the NVMe drive is securely installed in the PCIe slot
2) 'F2' or 'Delete' key to access BIOS setup
3) Navigate to PCIe slot settings and have them set to Legacy mode
4) Save changes and reset system
5) 'F2' or 'Delete' key to access BIOS setup again
6) Navigate to boot setup in your BIOS setup, and then you should be able to see the NVMe devices installed