Return DOM element in render function of React component

Here's a simple example.

render() {
   const newNode = document.createElement('p'); 
   return <div ref={(nodeElement) => {nodeElement && nodeElement.appendChild(newNode)}}/>
}

Render a normal JSX div. Use ref inside.

Inside the ref callback use .appendChild(node)

See https://reactjs.org/docs/refs-and-the-dom.html