I'm looking for a library that I can use for my Windows 10 UWP app. I just want to convert Youtube videos to mp3 and save in my PC. Everything in the best possible quality. I know videoLibrary but it is more for downloading videos. Thank you
You can use the python library & program youtube-dl to do this. You will either need python installed available for most platforms and then you can pip install youtube-dl to install it or you can download an exe and put it somewhere on your path.
You can then tell it that you only want to download the mp3 format (if available) with the command line option -f mp3 or, provided you also have FFMPEG installed and on your path, you can convert whatever is available to mp3 after download with:
youtube-dl -x URL --audio-format mp3