npm install --save lexical @lexical/react

import {$getRoot, $getSelection} from 'lexical';
import {useEffect} from 'react';

import LexicalComposer from '@lexical/react/LexicalComposer';
import LexicalPlainTextPlugin from '@lexical/react/LexicalPlainTextPlugin';
import LexicalContentEditable from '@lexical/react/LexicalContentEditable';
import {HistoryPlugin} from '@lexical/react/LexicalHistoryPlugin';
import LexicalOnChangePlugin from '@lexical/react/LexicalOnChangePlugin';
import {useLexicalComposerContext} from '@lexical/react/LexicalComposerContext';

const theme = {
  // Theme styling goes here
  ...
}

// When the editor changes, you can get notified via the
// LexicalOnChangePlugin!
function onChange(editorState) {
  editorState.read(() => {
    // Read the contents of the EditorState here.
    const root = $getRoot();
    const selection = $getSelection();

    console.log(root, selection);
  });
}

// Lexical React plugins are React components, which makes them
// highly composable. Furthermore, you can lazy load plugins if
// desired, so you don't pay the cost for plugins until you
// actually use them.
function MyCustomAutoFocusPlugin() {
  const [editor] = useLexicalComposerContext();

  useEffect(() => {
    // Focus the editor when the effect fires!
    editor.focus();
  }, [editor]);

  return null;
}

// Catch any errors that occur during Lexical updates and log them
// or throw them as needed. If you don't throw them, Lexical will
// try to recover gracefully without losing user data.
function onError(error) {
  console.error(error);
}

function Editor() {
  const initialConfig = {
    theme,
    onError,
  };

  return (
    <LexicalComposer initialConfig={initialConfig}>
      <LexicalPlainTextPlugin
        contentEditable={<LexicalContentEditable />}
        placeholder={<div>Enter some text...</div>}
      />
      <LexicalOnChangePlugin onChange={onChange} />
      <HistoryPlugin />
      <MyCustomAutoFocusPlugin />
    </LexicalComposer>
  );
}