This does not work with raw YouTube or other service links. You need a file host that can serve mp3s with a direct link, like copying the URL from Discord uploads or even Google Drive and Dropbox using the methods described here..
While playing MP3s or OGGs automatically is nigh impossible, unless you do something evil like cover the screen while the music's not playing so any click starts it (which would be a rule violation as far as I'm aware), this one might catch the attention of a viewer and cause them to play it out of curiosity.
Update: If you want to have it play automatically just in case someone has autoplay enabled for the website, add autoplay="autoplay" after loop="loop" in the code. This does not mean it will autoplay necessarily -- your browser would have to allow you to enable autoplay. Please do not complain if autoplay does not work, that's simply something they changed about web browsers and there's no way to get around it with the HTML spacehey gives you.
I recommend using internet radio stations for this one – currently, it's loaded with lainon.life's audio stream, but there's ones out there for stuff like vaporwave and such, so finding one playing whatever you like shouldn't be too much trouble.
Failing that though, you can just upload an mp3 or ogg to a filehost and have it play as a loop once someone clicks.
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Copy and paste this code into the "About me" section of your Profile to use it.
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