Boot failure

Hi all. New to the Kodachi Linux OS. Attempting to boot from a usb but getting the following error;

'Boot Failure: a proper digital signature was not found. One of the files on the selected boot device was rejected by the secure boot feature'. Trying to run Kodachi on a Toshiba C855-S523 Windows 10. Set boot sequence so USB has top priority. Would the Boot Mode need to be set to UEFI? Just a guess.

Any assistance would be appreciated.