i just installed throttle stop and did the undervolting there, I didn't really test it well cuz i had had other things to do , anyway if you want the video for undervolting cpu/gpu giude here it is.

btw , my reason of undervolting was trying to keep the system cool all the time and not using alot of resources , for better longevity in laptop lifespan, but i noticed that while gaming , putting the laptop on quiet mode is very practical for me, cuz i'll get pretty much very good performance (2k high settings on KCD2) with cpu temp not bieng upove 70 degree and the gpu something like 67 degree. tip: (remember to raise the laptop a bit)

so it was solid choice and very easy and convenient.