step three: handlePDFExport and it's onClick event

src/App.js

@@ -8,18 +8,25 @@ import './App.css';
 import 'bootstrap-4-grid/css/grid.min.css';
 
 class App extends Component {
+  constructor(props) {
+    super(props);
+    this.appContainer = React.createRef();
+  }
+  handlePDFExport = () => {
+    savePDF(ReactDOM.findDOMNode(this.appContainer), { paperSize: 'auto' });
+  }
   render() {
     return (
       <Ripple>
         <div className="bootstrap-wrapper">
-          <div className="app-container container">
+          <div className="app-container container" ref={(el) => this.appContainer = el}>
             <div className="row">
               <div className="col-xs-6 col-sm-6 col-md-6 col-lg-6 col-xl-6">
                 <h1>Sales | Q4 2018</h1>
               </div>
               <div className="col-xs-6 col-sm-6 col-md-6 col-lg-6 col-xl-6 buttons-right">
                 <Button primary={true}>Share</Button>
-                <Button>Export to PDF</Button>
+                <Button onClick={this.handlePDFExport}>Export to PDF</Button>
               </div>
             </div>
             <div className="row">