Create a Windows bootable USB on manjaro
Sometimes your Windows install needs to be reinstalled maybe because you don't want Linux anymore or because your Windows is not booting correctly.
In that case you can reinstall it using Ventoy, installing Windows will also delete your grub bootloader and you will lose access to any Linux distribution you are running alongside and will need to reinstall grub bootloader.
Install Ventoy from the repositories, make sure you plug your USB drive before launching Ventoy, after that make sure you select GPT under partition style, activating (secure boot support) option will depend if you have it active or not on your machine.
When this is done click install and it will create the partitions for you, this process is very fast and won't take long.
pamac install ventoy
You will end up with a partition named Ventoy available in your USB pen, that you need to copy your Windows ISO to, that is all you need to do.
Also have a look to a more extensive tutorial create a bootable Windows USB that also includes other available tools.