javascript:void function(){
  let a=new URL(location).searchParams.get("v"),
      b=new Intl.NumberFormat("en-US"),
      c=trustedTypes.createPolicy("forceInner", { createHTML: a => a });
  fetch(`https://returnyoutubedislikeapi.com/Votes?videoId=${a}`).then(a=>a?.text?.())
    .then(a => "{" === a[0] && JSON.parse(a) || a)
    .then(a => {
      console.log("dislikes",a); 
      a?.dislikes && document.body.insertAdjacentHTML(
        "beforeend",
        c.createHTML(`<div style="font-size:2rem;color:#ff0;position:absolute;right:2rem;top:8rem;z-index:10000;">
          ${b.format(a.dislikes)} dislikes
        </div>`)
      )
    })
}();