I got a 2hr long video which contains vocal and static/current noise. The "noise reduction" will not only remove the noise but also the vocal. How could I remove the noise only with Audacity?
The green arrows are the noise.
Based only at looking at the waveform, it seems the "noises" you're talking about are more looking like "clicks", so noise reduction algos can't work on this. You can try tu use the Audacity declicker named "Click removal" (https://manual.audacityteam.org/man/click_removal.html), but if the "noises" are not clicks, I don't know any processor who can identify and reduce random noises.
In the last case, you'll have to edit the entire track manually...
You have to identify frequencies of the noise and the voice (e.g. what do you want to remain in the track) by spectrum analyzer. After that you either apply low or high pass filter (if the freq of the noise is way upper/lower from your good part of the spectrum), or use EQ just for removing noise frequency individually. I tried to achieve the same goal with a track when my wife played live piano in a castello hall, but sounds of clinking cups in a coffee bar nearby remained nevertheless. I just managed to smooth the sound of the cups making them not so loud and sudden.