Play audio of a youtube video using js

i want to know please what is the easiest way to play just the audio of a youtube video in an html page.
Ive tried to take for example a link https://www.youtube.com/embed/fJ9rUzIMcZQ and to put it in some audio formats but i kinda got stucked and didnt really know what should i do.
For example i tried this format:

<audio controls>
<source src=”https://www.youtube.com/embed/fJ9rUzIMcZQ” type=”audio/ogg”>
</audio>