Already told you that the [Guide] How to get full NVMe support for all Systems with an AMI UEFI BIOS doesn’t work for you.
The only thing from there that you can learn is the OS installation method. period.
About this NEW NVMe mod presented here, it is the only chance that you may have to your motherboard, so just follow the post and links/pictures provided by users and get the work done.
I do not make this mod for anyone and i do not know all the steps for it, so learn and do it yourself with the feedback provided here from other users and they will help you, when they can.
Your device controller ID identified is correct for this mod, any more details wait for someone to answer with a more focused detail on your mod procedures.
If you dont know how to work with AMI bios tools, make dumps, backups…etc, then you have a higher probability of fail/breaking your motherboard.