Portal-v3.jsx

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

export function LandingPad() {
  return <div id="portal-root" />;
}

export function Portal (props) {
  const elRef = useRef(document.createElement("div"));
  const rootRef = useRef();

  useEffect(() => {
    rootRef.current = document && document.getElementById("portal-root");
    rootRef.current && rootRef.current.appendChild(elRef.current);

    return () => {
      rootRef.current && rootRef.current.removeChild(elRef.current);
    };
  }, []);

  return ReactDOM.createPortal(props.children, elRef.current);
}