sudo fdisk -l
probably /dev/sd*, * being a or b. The device is /dev/sd*, remove the number at the end if there is one.
sudo dd bs=4M if=path/to/iso of=/dev/sda status=progress oflag=sync
Download a SHA256SUMS
file or create one with the following format : [checksum] *[iso file name]
and add it to the same folder where the iso file is located then run the following command:
sha256sum -c SHA256SUMS 2>&1 | grep OK