When the application loads, go to the What do you want to do? page. Choose Create installation media for another PC. Choose your preferred language and whether the build should be 32-bit or 64-bit.
Make sure the flash drive is connected. You'll need at least 8 GB of free space. Any existing data on the flash drive will be deleted. Click Next when you’re ready to create the drive.
Congratulations! You now have a Windows 10 bootable USB drive.