I have downloaded debian iso in sub, then did
$ sudo dd bs=4M if=/Downloads/firmware-10.4.0-i386-DVD-1.iso of=/dev/sdb status=progress && sync
But the iso has saved in partition, instead of device itself: $lsblk:
sdb 8:16 1 14.4G 0 disk
├─sdb1 8:17 1 3.7G 0 part /media/user/Debian 10.4.0 i386 1
└─sdb2 8:18 1 2.2M 0 part
And from here Why does 'dd' not work for creating bootable USB? is mentioned, i cannot boot from partition. But from the command above, as seen, I have specified device /dev/sdb and not partition /dev/sdb*, so should I now try to dd again? or is here possibility to boot from partition? But in boot menu in start, there is only to boot from other devices such as /dev/sdc and I do do not see possibility to boot from /dev/sdb1 which now contains the iso, so how to boot the iso and installation?