I found this procedure on the webs and used it slightly modified, as outlined below.
Become root with sudo su -
Insert the USB drive, and find its device name.
lsblk sdk 8:160 1 31.6G 0 disk └─sdk1 8:161 1 13.7G 0 part /run/media/gill/OCTD
Unmount the partition.
Run fdisk with the device name and remove existing partitions.
Create a primary partition, make it bootable, and set the type to 7 (HPFS/NTFS/ExFAT). Write the changes and exit fdisk.
Create a FAT32 filesystem.
mkfs.vfat -F 32 /dev/sdk1
Mount the partition to a directory
mount /dev/sdk1 /media/usb
Mount the ISO image to a directory
mount -t udf -o loop,ro,unhide windows10.iso /var/tmp/w10
Copy all the files from the ISO to the USB directory
cp -arv /var/tmp/w10/* /media/usb
Write out the buffers to the USB stick
Unmount the ISO and the USB
umount /media/usb umount /var/tmp/w10
Remove the USB drive.