Meanwhile i wait a solution from @Lost_N_BIOS on the HP topic here : Thank’s
i’d like to ask you one more solution for this issue.
I’ve been flashing the original bios file with the build in App…
Loaded Windows O.S.
Extract the Bios with Aptio Afuwinx64 rom
Opened it with MMTools and add the Nvme module into CSMCore 
Flash back the modded ROM with Afuwin /GAN option
All seems to be gone well as now, switching on the machine, it’s visible the NVme SSD flashing at POST.
BUT… in Bios there is no UEFI secure boot ans actually, booting from a UEFI USB Drive with a Win10 ISO, the installation hang because it recognize that the
available disk is not bootable.
did i forgot something along the process?
Thank’s
@toxstoxs - You cannot add NVME mod (UEFI) into CMSCore (legacy), however looking at your image it doesn’t look like you did what you said (inserted NVME into CSM), so i think you are good to go
CSM is enabled by default for your BIOS, so secure boot mode enabled or disabled doesn’t matter and assume enabled otherwise no point to add CSM/Auto Setting
Follow all steps at #4 point of the “This is what you should do” section here - [Guide] How to get full NVMe support for all Systems with an AMI UEFI BIOS
Install from GPT initialized USB stick, to RAW NVME (no initialization or partitions etc).
Or, if you can’t make that work, maybe Secure Boot is disabled, which is dumb for them to add CSM in there then, anyway if this is case make USB MBR and then install to RAW NVME still
Also, you can probably flash mod BIOS on this system with EZ Flash, use stock name.extension
Confirmed working EZ Flash and Mod NVME BIOS + Proper OS install for these boards here on page 193 - [Guide] How to get full NVMe support for all Systems with an AMI UEFI BIOS (193)
The NVme module has been compressed inserted by hilight the CSMCore section before to "insert it"
the Win10 installation comes from a Rufus GPT USB drive with a 1909 Win10 Edition
Is the same USB i use for every UEFI installation on modern desktops.
As i mentioned before, even without any USB attached, the NVme SSD (it’s not RAW and already inizialized as it was previously used) start to have activity flash led… as it seems to be "found" from NVme Bios module added.
When Win10 prompt where it must be installed to, the NVme SSD isn’t accepted as marked as not bootable.
Yes, I see when I looked at your image. The way you mentioned it first, “Inserting into CMSCore” is also possible (and wrong), so until I saw your image I thought you did that since it’s what you described 
Sounds like “Secure Boot” or Win10/Win8 UEFI Mode is not enabled on this BIOS, even though CSM enabled is default, most likely due to BIOS is old and was made before these kind of BIOS settings were added into modern BIOS.
You will have to install in MBR mode, redo USB to MBR and make NVME RAW, then start install again
Make a new UEFI (MBR) Rufus USB Drive is not a problem…
never had before to put back in RAW an SSD… how to do it?
Bios is surely quite OLD (end 2013 i suppose) but it’s already "Graphic Stile" as modern UEFI Bios inferface…
possible that do not have a "boot link" to NVme UEFI module?
@Lost_N_BIOS
I would not use Rufus, or at least not UEFI/MBR (that sounds like Initialize as GPT, contradictory terms there)
You can go RAW by deleting all volumes in disk management, or use a free partition tool such as EaseUS, or you can use diskpart from CMD line as outlined below
>> Diskpart
>> List Disk
>> Select Disk (here, be 100% sure you select your correct disk #, this will match NVME drive # shown in Disk management, or you can probably tell by the size)
>> Clean
That is all. This system can boot to NVME, and I assume in GPT/UEFI Mode too, since user at above linked posts (second link in post #2, user -=N&N=- post 2885+2895) in the NVME mod thread didn’t mention having to use MBR or anything like we’ve discussed here.
You may want to send him a PM and see if he replies.
@Lost_N_BIOS
I found it could be failed by modding bios with mmtool and flashing with EZ update in bios,on some 6 series of ASUS mobos.
You must mod it with uefitool.I am just kind of interested in the difference of these two software.
You cannot flash mod BIOS at all with EZ flash (usually), so of course that will not work. Your mod BIOS looks OK, at least the insert, I can tell from your image above
However, where did you read that you have to edit this model with UEFITool (it may be possible that you do need to, but usually other way around though, some fail if you use UEFITool and you have to use MMTool instead) I found that out hard way sometimes, because i prefer UEFITool (v25 for this)
Some older boards let you flash mod BIOS with EZ Flash, I See I mentioned it’s confirmed OK on this model so you should be good there. Please link me to where you read that about MMTool/UEFITool. If needed I can make mod BIOS for you with UEFITool instead if you need.
Ohh! It’s you @gloobox , whole time I thought I was replying to OP 
Where do you read that about MMTool/UEFITool? See link I posted above #2, already confirmed all OK for NVME and EZ Flash on this exact model (Edit tool used not mentioned there, so can’t confirm)
@Lost_N_BIOS
The bios format of his mobo is ROM in ASUS official which doesn’t has any bios lock.It was OK in many of the ASUS 6 series mobos.
But only a tiny minority of these type of mobo was failed.So I think uefitool was the truth!
Yes, I know. Some rom still can’t flash mod BIOS with EZ flash though. BIOS Lock not being discussed here until you mentioned that
I always use UEFITool too, but on some old boards like this MMTool works better, not sure which is best here. I think he already flashed mod BIOS in anyway, I guess we should dump with FPT and confirm
@toxstoxs - Please do dump current BIOS with AFUWin and send to me so I can check >> AFUWin backup.bin /O
@toxstoxs - Thanks. That BIOS is a Mess! I see padding file messed up (main padding file, before main DXE volume). Plus you have NVME V4 Mod + NVME BIOS files (x3) form other boards that are NVME compatible by default + Samsung M2 in there as well.
You only need NvmExpressDxe_4.ffs by itself, and nothing else. I assume you didn’t touch that padding, so probably broken from either MMTool edit, or AFU /GAN flash (Not good!), at least your board specific details didn’t get messed up in there
Do you have a backup of BIOS before you flashed anything? If yes, send to me. If you do not, let me know, and I will make you proper BIOS mod to flash in with EZ Flash.
yes i know… the original modded Bios was exactly only with NvmExpressDxe_4.ffs module added to CSMCore. Not having a way to boot from the M.2 SSD i been messing up adding different modules… 
No padding mod has been made and yes… i use MMtool for modding the ROM file and used AFU /GAN for flashing.
I will reflash the original stock rom from Bios EZ Utility and send you a clean dump.
Which way is better to use for reading the rom ?
P.S. :
I flashed back the ORIGINAL Bios from Asus… then Dumped (read) the bios with 
Here is the file : CLICK
@Lost_N_BIOS
Yes, you only want that one module in there. What you did above (flash Stock BIOS from Asus), will not help with what I wanted to check, only old original backup would help (before you flashed any mod BIOS or used /GAN)
If you do not have any old BIOS backup, then we can only carry on with your BIOS broken as it is.
I do not get you…
which OLD Bios are you referring at?
The mobo apparently had always just one FW revision so i don’t understand which OLD Bios i should have.
I mean, ANY BIOS Backup you made BEFORE you flashed in ANY Modified BIOS, using ANY Method.
this should be the very FIRST dump i made where i added just the "correct" Nvme module.
hope it can help you
CLICK
No, you "Added" something to that, thus that is a modified BIOS. I want the file you dumped from BIOS, which you then edited. However, I doubt you did that, you probably edited stock BIOS, then flashed it.
If you did dump BIOS, before you edited it at first, send me that unedited first BIOS Dump/backup (not a stock BIOS, not an old stock BIOS, only an untouched BIOS backup from your system is what I mean)
The file i sent you before… (together with a pictur of AFUWin64GUI picture) is a CLEAN dump of stock Bios WITHOUT ANY EDIT or MOD’s
this : CLICK
That one is messed up too, ie you flashed by /GAN before making that dump, or edited the BIOS and flashed in other way before making that dump - or someone else did possibly, if you are not the original purchaser of this board.
However, all these BIOS are working (ie bootable) for you, so we can properly edit any of them with NVME Mod. Which do you want me to use? I will make you mod BIOS properly with both MMTool and UEFITool, then you can test