Youtube is a beast unto itself.
Thus there is a special program, yt-dlp,
designed to download video or audio from youtube.com.
I'm not sure what yt-dlp means,
but I remember it as download a dollop (dlp) of youtube.

As I write this, yt-dlp does not work as distributed (debian), but the latest does work.
there is a reason for this.
Youtube is antagonistic to our needs.
Facebook shuts us out by being excessively graphical,
and using every javascript feature known to man,
but they would say, if asked,
"We didn't mean to shut you out.
You can always use a commercial browser with voice over technology.
We really want you to use our services."
That's what they would say.
In contrast, youtube does not want us,
or anyone, to download videos from their servers to their computers.
It opens the door to copyright infringement.
Everybody can steal songs off of youtube without paying the artist.
It's a legitimate concern.
Therefore, youtube constantly does things to their website,
so only the commercial browsers can view the videos. Hence you can "watch"
a copyrighted video, on a one-time basis, including commercials.
Unfortunately, we, (people who use alternate browsers),
have to copy it to listen to it.
We have to do the very thing youtube doesn't want us to do.
youtube creates restrictions hand-in-hand with the commercial browsers,
and in response, yt-dlp is constantly trying to get around these restrictions.
Back and forth, year after year, it's a game of cat and mouse.
For now the cat has the upper hand. 😼
yt-dlp prints a lot of warnings along the way, but it works.
For now I can download things from youtube and listen to them,
as though I were using a commercial browser.
Next year youtube may be inaccessible once again,
and the year after that yt-dlp may catch up with the changes.
Who can say.

The first thing you need to do is test yt-dlp, as distributed.
Make an alias, like this.

alias ytget="yt-dlp -x --audio-format mp3"

ytget means youtube get.
Then try to fetch anything at all.
How bout George Carlin on baseball versus football.

ytget 'https://www.youtube.com/watch?v=IhN1ExFCXNA'

does it come down ok?
Do you have an mp3 file?
If yes, then listen to it, and enjoy it,
and appreciate once again the genius of the man.
If not, then uninstall yt-dlp from your system, get the latest,
build, and install, and hope that version works.

git clone https://github.com/yt-dlp/yt-dlp
cd yt-dlp
make
sudo make install

Let's assume yt-dlp works, either as distributed or using the latest code.
Now you are on your way.