how to add js inside react code example

Example 1: import a script to my react componetn

import React,{Component} from "react";
import ReactDOM from "react-dom";

import "./styles.css";

class App extends Component {
  componentDidMount() {
    const script = document.createElement("script");    script.async = true;    script.src = "https://some-scripturl.js";    this.div.appendChild(script);  }
  render() {
    return (
      <div className="App" ref={el => (this.div = el)}>        <h1>Hello react</h1>
        {/* Script is inserted here */}
      </div>
    );
  }
}

export default App;

Example 2: how to import js via script in react

import { useEffect } from 'react';

const useScript = url => {
  useEffect(() => {
    const script = document.createElement('script');

    script.src = url;
    script.async = true;

    document.body.appendChild(script);

    return () => {
      document.body.removeChild(script);
    }
  }, [url]);
};

export default useScript;