I have just acquired an Asus VivoBook 15 and have no Boot options in BIOS. I want to install Windows 10 (x64), since there is no existing OS on the system.
Secure Boot and Fast Boot are disabled and can't see any CSM or Legacy options anywhere.
The USB is bootable, as I have tested it on a different laptop. Delete Boot Option also does not have any other options (nothing to delete).
Boot options:
Boot menu: