you've already got music autoplaying on your profile so i might be too late but here's how just in case you still need help:
use this code:
<iframe width="0" height="0" src="https://www.youtube.com/embed/LINK HERE?autoplay=1&loop=1&controls=1" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="" loading="lazy">
</iframe>
go to a youtube video with the link you want and press "share". copy the bit between "youtu.be/" and the closest "?", and paste it in the code where it says "LINK HERE".
put it in your about me or the html/css code section, whatever u like. hope this helped!