How to undervolt RTX 3070?

Issue: Loud clicking noise (probably coming from RTX 3070 fan)

Goal: Undervolt GPU only(reduce noise), not underclock (do not want to mess up computer).

I contacted Dell Support regarding noise, a representative run test on my PC remotely, and did not find any issues. He said Undervolting GPU is not suggested by Dell, and did not say why.

I have no ideas what to do, watched a few youtube videos, still cannot figured out. I have installed Unigine Heaven Benchmark and MSI Afterburner , see attached.

How to read benchmark result(did it when PC is idle)?

What exactly do I need to do next?

Thanks.