Display an iFrame on a listing page

insert_iframe_listing_page.js

if(typeof Kr !== 'undefined' && typeof Kr.Listing !== 'undefined' && Kr.Listing !== null){
    if(Kr.Listing.id === YOUR_LISTING_ID) {
        var iframe = document.createElement('iframe');
        iframe.style.width="100%";
        iframe.style.height="300px";
        iframe.src = "YOUR_IFRAME_URL_SRC";
        let container = document.getElementsByClassName('container listing_container_main_wrapper');
        container[0].appendChild(iframe);    
    }
}