HTMLIFrameElement: src property

The HTMLIFrameElement.src A string that reflects the src HTML attribute, containing the address of the content to be embedded.

Note that programmatically removing an <iframe>'s src attribute (e.g. via Element.removeAttribute()) causes about:blank to be loaded in the frame.

src = iframeElt.src
iframeElt.src= src

const iframe = document.createElement("iframe");
iframe.src = "/";
const body = document.querySelector("body");
body.appendChild(iframe); // Fetch the image using the complete URL as the referrer