nvidia-smi command not found : ERROR with secure boot enabled

I found this post: https://askubuntu.com/questions/902636/nvidia-smi-command-not-found-ubuntu-16-04/903781and,Which says that with IUEF secure boot enabled nvidia-smi could not found in ubuntu:

$ nvidia-smi
nvidia-smi: command not found

Actually with secure boot enabled, UBUNTU could not found the addtional Nvidia GPU.

Any idea on how to enable secure boot with nvidai driver funcioning?

I found this article on solving the secure boot issue with virtual box, just still have little idea on how MOK manager works:

https://stegard.net/2016/10/virtualbox-secure-boot-ubuntu-fail/

Yes, with secure boot enabled, ubuntu doesn’t show nvidia-smi. It would output some message with NVIDIA driver is not installed properly.

You can disable secure boot from the BIOS of you machine.

I tried several option with secure boot enable, just doesn’t work.