Is there a different approach that is more stable and works no matter whether it is j or h or anything else?

Can that part be written a different way in the code?

const iframe = player.h; https://jsfiddle.net/eo8s4zt9/

function onPlayerReady(event) {
    player = event.target;
    player.setVolume(100);
    shufflePlaylist(player);
    const iframe = player.h;
    iframe.dispatchEvent(events.afterPlayerReady);
  }

    const iframe = player.h;
    const eventHandler = eventHandlers.afterPlayerReady;
    iframe.addEventListener("afterPlayerReady", eventHandler);
  }

I was trying different things and found this that works.

Instead of using this: const iframe = player.h;

I can do this: https://jsfiddle.net/gobt8xe7/

Is this good?

    const iframe = document.querySelector("iframe");
    iframe.dispatchEvent(events.afterPlayerReady);
  }
    const iframe = document.querySelector("iframe");
    const eventHandler = eventHandlers.afterPlayerReady;
    iframe.addEventListener("afterPlayerReady", eventHandler);
  }

Improving on that I can then do this: https://jsfiddle.net/z1kywacL/

function getIframe() {
    return document.querySelector("iframe");
  }

  function shufflePlaylist(player) {
    player.setShuffle(true);
    player.playVideoAt(0);
    player.stopVideo();
  }

  function onPlayerReady(event) {
    player = event.target;
    player.setVolume(100);
    shufflePlaylist(player);
    const iframe = getIframe();
    iframe.dispatchEvent(events.afterPlayerReady);
  }

  function addPlayer(video) {

    const playlist = "0dgNc5S8cLI,mnfmQe8Mv1g,-Xgi_way56U,CHahce95B1g";

    const config = {
      height: 360,
      host: "https://www.youtube-nocookie.com",
      width: 640
    };
    config.playerVars = {
      autoplay: 0,
      cc_load_policy: 0,
      controls: 1,
      disablekb: 1,
      fs: 0,
      iv_load_policy: 3,
      loop: 1,
      playlist,
      rel: 0
    };
    config.events = {
      "onReady": onPlayerReady
    };

    player = new YT.Player(video, config);

    const iframe = getIframe();
    const eventHandler = eventHandlers.afterPlayerReady;
    iframe.addEventListener("afterPlayerReady", eventHandler);
  }