not being able to flash my san usb drive

So I was able to flash my usb drive before with an .iso but that was the wrong thing to flash on the usb, so i formatted the usb and tried the flash the right thing on it which was a .img, but to no success this time so I tried to flash the .iso again but that also failed to flash this time. could someone help me figure out the problem? i think its because the I formatted it

Hello, what kind of error are you seeing that tells you the flash of the .iso failed?