The issue you are facing is a common one with older motherboards. Only until the last 5-7 years did motherboards allow you to install an operating system from USB. Just to be clear, this issue is a motherboard issue 100%.
According to Sony's Website. Your computer is around 10 years old. It's very doubtful your motherboard will allow such functionality. But without the exact model of the motherboard, it would be impossible to say. The fact that you mention it's not in the bios setting, should give your answer right there.
My guess is you probably assumed loading an operating system via usb was always "a thing". But USB flash drives are actually a very recent technology
Solution: You'll need to install the OS via CD/DVD rom.