If your Intel® NUC is not included in the Product list below, use the Intel® Integrator Toolkit or Intel® VCUST instead. Intel® AptioV Integrator Tools are only supported by the AptioV based products. Only key combination that make USB flash for few times around 8-10 times in my case is Fn + r. Otherwise, you might need to wait for your SPI programmer to arrive.

you might need to press + , or key + before plugging in AC adapter (battery removed).
How to use these utilities: See the User Guides in each folder. Did you press any keys on the keyboard i.e.
You can use the target system or a different system to enact the changes.

Settings can be changed by using either a text editor or a setup program.

Variables can be extracted directly from the BIOS.
When using iSetupCfg on the target system, it creates a script file that lists all setup questions, which can be modified and used as an input to change the current NVRAM setup variables. ISetupCfg - Intel® iSetupCfg is a command line tool that provides you an easy way to update NVRAM variables from within the EFI, Linux*, or Windows*-based environment. ICHLogo - The Intel iCHLogo application allows you to replace the logo inside the Aptio Firmware file or Capsule file with a new one.

This utility works with Aptio firmware with SMBIOS support. It allows you to modify strings associated with SMBIOS tables. IDMIEdit - iDMIEdit stands for Desktop Management Interface Edit. IFlashV - The iFlashV application operates in command line mode for OEM key activation/ editing, BIOS update, etc. Not sure which tool to use? Refer to the descriptions below: Intel® AptioV Integrator Tools are designed to assist integrators (who usually work in manufacturing or enterprise environments) with the process of BIOS/SMBIOS customization, OEM Windows* product key injection (OEM Activation 3.0, OA3), changing the Logo, etc.

Aptio change logo utility