React pass a const from child component to parent

Hello, I have created a new const (a concatenated string) to be used as a URL for a fetch function. I validated the concatenated string works by console.log and now I want to pass it to another component that has the fetch function, but I can’t seem to get that part right, any suggestions? Thanks for your help!

Child component: “URLconcatenate.js”

import React from 'react'

const apiRequest = ''
const stockSymbol = "AAPL";
const tokenstring = '&token=cmhauvpr01qmgvct6qk0cmhauvpr01qmgvct6qkg'
const urlString = apiRequest + stockSymbol + tokenstring

//this works fine!

//I am not sure if I'm doing this part right
function URLconcatenate() {
    return (

export default URLconcatenate

Parent component: “Datafetch.js”

import URLconcatenate from './URLconcatenate';
import { useState, useEffect } from 'react';

const Datafetch = () => {
    const [price, setPrice] = useState([]);
    useEffect(() => {
        //this is the new way I want to pass the concatenated URL
        fetch({ urlString })
        //this is the older, hard-coded way
            .then((response) => {
                return response.json();
            .then((data) => {
    }, []);
    return (
            { => (
                <p key={thePrice.c}>Today's price for AAPL is: ${thePrice.c}</p>
        </div >

export default Datafetch