I am trying to create a function that empties a video container of its contents (thumbnail / playbutton) and replace it with an iframe of for example vimeo or youtube.

So far I got this:

replaceIframe(){
    const parser = new DOMParser();
    const videoContainer = document.querySelector('#landingspage .video-container');
    const iframe = document.querySelector('#landingspage .iframe-container').innerHTML;
    const iframeHTML = parser.parseFromString(iframe, "text/html");

    console.log(iframeHTML);

    if(videoContainer !== null){
        videoContainer.addEventListener('click', (ev) => {
            ev.preventDefault();
            videoContainer.replaceChildren(iframeHTML);
        });
    }
}

But this gives me the error:

Uncaught DOMException: Failed to execute 'replaceChildren' on 'Element': Nodes of type '#document' may not be inserted inside nodes of type 'DIV'.
    at HTMLDivElement.

How can I fix this? I first tried it without the parser object but then it just replaces the contents with a string of the iframe html.