Use fdisk or equivalent to prepare the USB disk (at least 7G).
Remove any existing partition (d), create a GPT table (g).
Add a UEFI partition 1G sized, and 6G++ one of type 11 (Microsoft basic data).
Save the partitio table (w).
Format the UEFi partition and the NTFS one :
mkfs -t vfat /dev/sdZ1 mkfs -t ntfs /dev/sdZ2
Download a Win10 CD from Microsoft and mount it with :
sudo mount -o loop -t iso9660 /chemin/vers/image.iso /mnt
Then :
(WARNIN : not tested!)
(source from https://techbit.ca/2019/02/creating-a-bootable-windows-10-uefi-usb-drive-using-linux/ where can be found less arid instructions…)