АНасо, Thank you for posting in the Intel® Communities Support.
I looked in the TPS (Technical Product Specification) of the Intel® NUC Kit NUC8i3BEK and the only thing in reference to the SMB bus describes that the hardware monitoring and fan control subsystem is based on an ITE Tech. IT8987 E-VG embedded controller, which supports among other things the SMBus interface, page 19:
So, in order for us to further assist you, could you please provide a description of what do you mean with "use" the SMB bus with the Intel® NUC?
Is there a project that you are currently working on?
Intel Customer Support Technician
Under Contract to Intel Corporation
The SMBus capability is present in the chipset (PCH component), but is not exposed anyplace on the board for general-purpose access (it may be exposed in the M.2 Type B/M connector). Specifically, there is no support for a Custom Solutions Header like you will find on some other NUC models.