Add the Bookmark with this code as url

yt2mp3.venipa.net-bookmark-convert

javascript:"use strict";!function(){const e=new URL(window.location.href);const t=/(?:youtube\.com\/(?:[^\/]+\/.+\/|(?:v|e(?:mbed)?)\/|.*[?&]v=)|youtu\.be\/)([^"&?\/ ]{11})/i;if(!t.test(e.href))return;const o=t.exec(e.href)[1];var n,i;o&&(n=o,(i=document.createElement("a")).style="position: absolute;  z-index: -1; width: 0; height: 0; opacity: 0",i.href="https://yt2mp3.venipa.net/video/"+n,i.target="_blank",i.click(),i.remove())}();