Installing nvidia driver for quadro RTX 6000 on Ubuntu 18.04/20.04

I just recently bought HP workstation z4, which contains Nvidia Quadro RTX 6000. I have spent days trying to install the right nvidia driver and cuda-toolkit, but so far not a single solution online work. I have tried both Ubuntu 18.04 and Ubuntu 20.04, neither of them could solve the problem. By running nvidia-smi it still give the “NVIDIA-SMI has failed because it couldn’t communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running.” all the time. I’ve attached one of the bug report of the lastest try of mine just in case it would help. Honestly, I really don’t understand why it has to be this complicate for the non-expert user to have to figure it out.
Thank in advance for any help to guide me on how should I do.

Dan

nvidia-bug-report.log.gz (115.5 KB)