$ npm install smartblock --save

<script src="https://unpkg.com/smartblock@latest/dist/standalone/index.js"></script>

import * as React from 'react';
import { render } from 'react-dom';
import 'smartblock/css/smartblock.css';
import { SmartBlock, Extensions } from 'smartblock';

render(<>
  <SmartBlock
    extensions={Extensions}
    html={'<h2>Hello World</h2><p>hello</p>'}
    onChange={({ json, html }) => { console.log(json, html);}}
  />
  </>, document.getElementById("app")
);

<link rel="stylesheet" href="https://unpkg.com/smartblock@latest/css/smartblock.css" />
<script src="https://unpkg.com/smartblock@latest/dist/standalone/index.js"></script>
<script src="https://unpkg.com/smartblock@latest/dist/standalone/extensions/index.js"></script>
<!-- You can use smartblock without using JSX -->
<!-- bundle size is much smaller than the package build with react !-->
<script>
SmartBlock.Editor('#app', {
  html: '<h2>Hello World</h2><p>hello</p>',
  extensions: SmartBlock.Extensions,
  onChange: function(result) {
    console.log(result.json, result.html);
  }
});
</script>