That's a loaded question! You will need to do two things:
That's a quick rundown. Intel has a help page regarding troubleshooting of audio issues here: https://www.intel.com/content/www/us/en/support/articles/000032598/mini-pcs.html. If you have additional questions (and I am sure you do), feel free to ask. Remember, there are no dumb questions.
Hope this gets you started,
the issue is not the software but the needed hardware. It looks like the audio jac supports stereo out but only mono in. Is there a cable recommended for recording ?
Ah, that's right; I always forget about this issue because I regularly use a separate USB audio capture device. Here's an example of such a device: https://www.amazon.com/DIGITNOW-Capture-Grabber-Cassette-Converter/dp/B079CBGDST. Note that I use this particular device as an example only (do not misconstrue as an endorsement); the device I have actually came with a Roxio Software package that I purchased a few year ago. I take the line out signal from my received and feed it into this device. I then capture the audio in its digital form.
what’ the source of your audio i use a focusrite scarlett 2i2 and i’m able to record instruments and microphones if needed, you can also plug anything with the xlr input and that’d be any source, but if you wanna record something average like another pc you could use the audio jack from the nuc and you should see it as an audio source if settled as microphone or line in