title: Iframe option in google apps-script
body: <p>Is it possible to display a website (eg. www.google.com ) using iframe  in the sidebar of google docs while developing using app-script  iframe .'X-Frame-Options' to 'same-origin' , error is occurring . I tried setXFrameOptionsMode(HtmlService.XFrameOptionsMode.ALLOWALL);</p>
  
  <p>Still the same error occurs.</p>
  
  <h1>Screenshot Link</h1>
  
  <p><a href="https://i.stack.imgur.com/wk9vM.png" rel="nofollow noreferrer">Click this link for screenshot of error</a></p>
  
  <p>===========</p>
  
  <h1>Code.gs</h1>
  
  <pre><code>function onInstall(e) {
    onOpen(e);
  }
  function onOpen(e){
    var ui = DocumentApp.getUi();
    ui.createMenu("IframeOptions").addItem("iFrame",'sviFrame').addToUi();
  }
  function sviFrame(){
   var iframe =  HtmlService.createHtmlOutputFromFile('Iframe').setSandboxMode(HtmlService.SandboxMode.IFRAME).setXFrameOptionsMode(HtmlService.XFrameOptionsMode.ALLOWALL);
  
    /*var template = HtmlService.createTemplateFromFile('Iframe')
      .evaluate()
      .setXFrameOptionsMode(HtmlService.XFrameOptionsMode.ALLOWALL);*/
  
   DocumentApp.getUi().showSidebar(iframe);
  }
  </code></pre>
  
  <p>=============</p>
  
  <h1>Iframe.html</h1>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
    &lt;head&gt;
    &lt;base target="_top"&gt;
    &lt;/head&gt;
    &lt;body&gt;
      &lt;iframe src="https://www.google.com" height="1500" width="100%"&gt;&lt;/iframe&gt;
    &lt;/body&gt;
    &lt;script&gt;
    alert(google.script.sandbox.mode);
    &lt;/script&gt;
  &lt;/html&gt;
  </code></pre>