Hello!
To make nvme working correctly, I need to modify the AMI BIOS with the addition UEFI and nvme driver. Please tell me, is this even possible?

mainboard is supermicro X8DTT-F

in one forum, I found a mention that it is possible to do this using UBU, but now I have doubts about this

I will be grateful for any help

Sorry but UBU is not a Legacy/UEFI transformer tool, its a module updater tool mostly used with AMI Aptio UEFI.
And i can that, maybe wot u saw was a much rare tiny transformation on an hybrid UEFI bios, those were transition bios AMICore8/Aptio

U can try this: [Experimental] NVMe Option ROM