Modify iframe.src without entry to history object

const urls = [
  "http://bing.com",
  "http://google.com",
  "http://duckduckgo.com"
];

function next() {
  if(urls.length==0) return;
  const original = document.getElementsByTagName("iframe")[0];
  const newFrame = document.createElement("iframe");
  newFrame.src = urls.pop();
  original.parentNode.replaceChild(newFrame, original);
}

nextbtn.addEventListener("click", () => next());

iframe {
  width: 300px;
  height:300px;
}

<p>let's test some iframes</p>
<button id="nextbtn">next</button>
  <iframe />