Copy and paste the link of the YouTube-Video into the edit-box. You can also provide the link of the YouTube playlist.
Check the option to download only the audio element (music without huge video).
Set audio format to MP3 or M4A (cover art is supported only for MP3 or M4A audio formats).
Check the option to add thumbnail in the audio file as a cover art.
Push Download button.
Open the output folder with downloaded music.