title: Button on HTML calling a google script
body: <p>I have an code.gs that creates a menu that opens a sidebar with html.
  My html is like that:</p>
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
    &lt;head&gt;
      &lt;base target=&quot;_top&quot;&gt;
      &lt;link rel=&quot;stylesheet&quot; href=&quot;https://ssl.gstatic.com/docs/script/css/add-ons1.css&quot;&gt;
    &lt;/head&gt;
    &lt;body&gt;
       &lt;button onclick='ativarFeedbacks()'&gt;Feedback&lt;/button&gt;
       &lt;div id=&quot;aviso&quot;&gt;aaasaaa&lt;/div&gt;
       &lt;script&gt;
          
          function callback(resposta) {
             document.getElementById(&quot;aviso&quot;).innerHTML=resposta;
          }
       
          function ativarFeedbacks() {
             google.script.run.withSuccessHandler(callback).escrever();
          }
          
       &lt;/script&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  <p>My code.gs is like this:</p>
  <pre><code>function onOpen(e) {
    FormApp.getUi()
        .createAddonMenu()
        .addItem('Configurar feedbacks', 'showSidebar')
        .addToUi();
  }
  
  function showSidebar() {
    var ui = HtmlService.createHtmlOutputFromFile('teste2')
        .setTitle('Feedback');
    FormApp.getUi().showSidebar(ui);
  }
  
  function escrever(){
    return &quot;&lt;h1&gt; salve salve &lt;/h1&gt;&quot;
  }
  </code></pre>
  <p>But, when I run onOpen, I open the sidebar and press the button, nothing happens. My innerHTML on id &quot;aviso&quot; doesn't change like nothing was returned by escrever(). I am not understanding this behavior. What should I do?</p>