No USB Boot option for Aspire 5
I have a new Aspire 5, System BIOS v1.07. I also have a bootable Ubuntu image on a USB 3 drive, which is plugged into the front left-side USB port. I am trying to boot from this drive so I can remove Windows and install Ubuntu 18.04, but the USB drive is not being recognized as a bootable device. I press the F2 key on power-on to get the InsydeH2O Setup Utility. On the Main menu, I have enabled F12 Boot Menu, and disabled Fast Boot. Still, on the Boot menu, I see only the Windows Boot Manager. If I press F12 during boot, I see only the Windows Boot Manager. How can I get the system to recognize my bootable USB?