React need help

I am studying React with Bootstrap. What else do I need to post to see this in the browser ?

<!DOCTYPE html>
<html>
 <script src="https://cdnjs.cloudflare.com/ajax/libs/react/<react-version>/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/<react-version>/react-dom.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-bootstrap/<version>/react-bootstrap.min.js"></script>
<body>
<div ></div>
<script>
 const buttonsInstance = (
  <ButtonToolbar>
    <Button bsStyle="primary" bsSize="large" active>Primary button</Button>
    <Button bsSize="large" active>Button</Button>
  </ButtonToolbar>
);
ReactDOM.render(buttonsInstance, mountNode);
</script>
 </body>
</html>

You haven’t set your mountNode, but this doesn’t look like a Meteor question.

I don’t know how set mountNode. Where can see how it make? I recently began to study how to use React with Bootstrap.

i would advice to check some react tutorials first before you add meteor or even bootstrap into the mix.

But to answer your question: you don’t set mountNode as rob mentioned. The second argument of ReactDom.render is the dom element where the component gets attached to. See https://reactjs.org/docs/rendering-elements.html#rendering-an-element-into-the-dom for more information