Create Bootable usb for Win 10 1909 from Ubuntu/KDE Neon

I have KDE Neon installed on my laptop and I want to dual boot with windows. I downloaded Windows-10 ISO from Microsoft download page. This is Windows 1909 version.

I have tried many approaches provided online to create bootable usb for windows:

1. Formatting usb stick as fat32 doesn't work since one file is >4GB in ISO.
2. dd: Stick not shown in boot menu.
3. Mount ISO and copy to stick(I tried ntfs, exfat and udf) also doesn't work. Stick not shown in boot menu.
4. I can not use media creation tool or rufus since I don't have a windows system.
5. UNetbootin doesn't detect the USB stick.

P.S. I am trying to boot in uefi mode since my kde neon is booting in that mode.

Why is microsoft making it very difficult to install windows who doesn't have windows already?

Use multisystem

On boot go to bios, change boot mode to Legacy and turn off secure boot. Save and restart. Boot from the flash drive and windows will be in selinux option. Install... Restart. and enable again secure boot but leave it on legacy (otherwise your linux won't run) If it doesn't show in the grub after that.. Just run your linux and just run:

sudo update-grub

after that restart and you should see and able to boot in to windows as well.

Rufus and UEFI:NTFS developer here. If you are familiar enough with Linux commands (and are very careful with the targets you use for these commands, so that you don't end up erasing the wrong drive by mistake) the following should get you sorted:

• Create a GPT partitioned USB drive with 2 partitions, both of type Microsoft basic data partition, the first one occupying the whole drive minus 512 KB (note that it's kilobytes, not megabytes) and the second one being 512 KB in size. On the command line, you can use gdisk to do that, but make sure to select the disk device that is your USB drive (for instance, if your USB drive is seen as /dev/sde then you should use the command gdisk /dev/sde).
• Format the first partition to NTFS, mount it, and extract the whole content of the Windows 1909 ISO onto it.
• Use dd to copy the 512 KB uefi-ntfs.img data which you can download from here onto the second partition. For instance, provided that your USB drive is seen as /dev/sde, then a command like dd if=uefi-ntfs.img of=/dev/sde2 should do (since sde2 would be the second partition from the sde drive — This is the part where you need to make double sure to use the right device!)
• If needed, temporarily disable Secure Boot on your target system (you can re-enable it after Windows has been installed).

Once you have done that, if you plug the USB on your target machine, you should be presented with the option to boot from it in UEFI mode, which will launch the UEFI:NTFS bootloader, which in turn should enable your system to boot the Windows UEFI bootloaders that you extracted onto the first partition and proceed with your Windows installation.