@rdamicojr
As you can read within >this< Guide, you will never see your NVMe SSD as bootable device within the BIOS of your old mainboard, but nevertheless you should be able to get Win10/11 installed onto it, if you follow my advices layed down within the “Step 4” chapter of my guide.
Good luck!
By the way:
After having enabled the “CSM Mode” within the BIOS, a device named “PATA” or “PATA_SS” should be listed within the BIOS as bootable device. This will be the proof, that the NVMe module has been inserted successfully, but nevertheless the booting will not work this way (as mentioned within my Guide).