Helping troubleshoot a Redux Firestore project

MyQuizList.js

import React from "react";
import { compose } from "redux";
import { connect } from "react-redux";
import { useSelector } from "react-redux";
import {
  firestoreConnect,
  useFirestoreConnect,
  withFirestore,
  isLoaded,
  isEmpty,
} from "react-redux-firebase";
import firebase from "firebase";
import Quiz from "./Quiz";
const myQuizzesReduxName = "myQuizzes";

function MyQuizList(props) {
  const auth = props.firebase.auth();
  const currentUserId = auth.currentUser.uid;

  let db = firebase.firestore();
  let quizzesRef = db
    .collection("quizzes")
    .where("author", "==", currentUserId);

  // console.log("My Quizzes", quizzesRef.get());

  let nowVisible;

  quizzesRef
    .get()
    .then(function (myQuizzes) {
      if (isLoaded(myQuizzes)) {
        return (
          <React.Fragment>
            myQuizzes.forEach(function(doc){<div>TESTING</div>})
          </React.Fragment>
        )
      }
    })
    .catch(function (error) {
      console.error("Error in MyQuizList component:", error);
    });
  debugger;
  return <React.Fragment>{nowVisible}</React.Fragment>;
}

export default withFirestore(MyQuizList);

// currentVisibleComponent =
// <React.Fragment>

// <Quiz quizName="outside!" />
// </React.Fragment>
//
// )
// }