use-post-message.jsx

const usePostMessageHandler = (messageKey, callback) => {
  useEffect(() => {
    const receiveMessage = event => {
      if (event.data === messageKey) {
        callback(event);
      }
    };

    window.addEventListener("message", receiveMessage, false);
    return () => {
      window.removeEventListener("message", receiveMessage);
    };
  }, [callback, messageKey]);
};

usePostMessageHandler("completed-forms:refresh", event => {
  setRefreshMarker(+new Date());
});

const NotifyParentWindow = ({ event }) => {
  useEffect(() => {
    window.onbeforeunload = () => {
      if (window.opener) {
        window.opener.postMessage(event);
      }
    };

    return () => {
      window.onbeforeunload = undefined;
    };
  }, [event]);
  return null;
};

<NotifyParentWindow event="completed-forms:refresh" />;