3 On the command line
To show the USB drive among all storage partitions and volumes on your computer use: lsblk. You can also use: df.
Suppose it may be /dev/sdy1 . Unmount it with: sudo umount /dev/sdy1.
To format drive with the FAT32 file system format: sudo mkfs.vfat -F 32 /dev/sdy1.