@Sparky_s_Adventure >Here< is the Guide about how to do the NVMe related BIOS modification yourself.
Good luck!
Edit:
There is no need for any NVMe related BIOS modification, if you flash one of the latest BIOSes, which were released by Gigabyte for your mainboard. They do natively support booting off an NVMe SSD.
I tried that specific guide, I got errors when trying to modify it. I know later retail bioses have the NVMe support, but I would like to modify this specific bios.