<h5>postbid iframe</h5>
<iframe id='postbid_iframe' 
    FRAMEBORDER="0"
    SCROLLING="no"
    MARGINHEIGHT="0"
    MARGINWIDTH="0"
    TOPMARGIN="0" 
    LEFTMARGIN="0" 
    ALLOWTRANSPARENCY="true"
    WIDTH="0"
    HEIGHT="0">
</iframe>
   
  
    var sizes = [
    [300, 250]
];
var PREBID_TIMEOUT = 1000;            
var adUnits = [{
    code: 'postbid_iframe',
    mediaTypes: {
        banner: {
            sizes: sizes
        }
    },
    bids: [{
        bidder: 'appnexus',
        params: {
            placementId: 13144370
        }
    }]
}];
var pbjs = pbjs || {};
pbjs.que = pbjs.que || [];
pbjs.que.push(function() {
    pbjs.addAdUnits(adUnits);
    pbjs.requestBids({
        timeout: PREBID_TIMEOUT,
        bidsBackHandler: function() {
            var iframe = document.getElementById('postbid_iframe');
            var iframeDoc = iframe.contentWindow.document;
            var adServerTargeting = pbjs.getAdserverTargetingForAdUnitCode('postbid_iframe');
            // If any bidders return any creatives
            if (adServerTargeting && adServerTargeting['hb_adid']) {
                pbjs.renderAd(iframeDoc, adServerTargeting['hb_adid']);
            } else {
                iframe.width = sizes[0][0];
                iframe.height = sizes[0][1];
                iframeDoc.write('' + passbackTagHtml + '
  
  
');
                iframeDoc.close();
            }
        }
    });
});
// Define the passback HTML tag here.
// Note that this tag is usually in either Script tag form or iFrame form. 
var passbackTagHtml = 'TO ADD';
   
  
    <html>
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Postbid Example</title>
    <!-- required scripts -->
    <script async src="//cdn.jsdelivr.net/npm/prebid.js@latest/dist/not-for-prod/prebid.js"></script>
    <script async src="https://securepubads.g.doubleclick.net/tag/js/gpt.js"></script>
  </head>
  <body>
  
  <!-- javascript -->
  <script>var sizes = [
    [300, 250]
];
var PREBID_TIMEOUT = 1000;            
var adUnits = [{
    code: 'postbid_iframe',
    mediaTypes: {
        banner: {
            sizes: sizes
        }
    },
    bids: [{
        bidder: 'appnexus',
        params: {
            placementId: 13144370
        }
    }]
}];
var pbjs = pbjs || {};
pbjs.que = pbjs.que || [];
pbjs.que.push(function() {
    pbjs.addAdUnits(adUnits);
    pbjs.requestBids({
        timeout: PREBID_TIMEOUT,
        bidsBackHandler: function() {
            var iframe = document.getElementById('postbid_iframe');
            var iframeDoc = iframe.contentWindow.document;
            var adServerTargeting = pbjs.getAdserverTargetingForAdUnitCode('postbid_iframe');
            // If any bidders return any creatives
            if (adServerTargeting && adServerTargeting['hb_adid']) {
                pbjs.renderAd(iframeDoc, adServerTargeting['hb_adid']);
            } else {
                iframe.width = sizes[0][0];
                iframe.height = sizes[0][1];
                iframeDoc.write('' + passbackTagHtml + '');
                iframeDoc.close();
            }
        }
    });
});
// Define the passback HTML tag here.
// Note that this tag is usually in either Script tag form or iFrame form. 
var passbackTagHtml = 'TO ADD';
</script>
  <!-- html -->
  <h5>postbid iframe</h5>
<iframe id='postbid_iframe' 
    FRAMEBORDER="0"
    SCROLLING="no"
    MARGINHEIGHT="0"
    MARGINWIDTH="0"
    TOPMARGIN="0" 
    LEFTMARGIN="0" 
    ALLOWTRANSPARENCY="true"
    WIDTH="0"
    HEIGHT="0">
</iframe>
  </body>
</html>