How to fetch data from node server - node.js

Question

I'm new to react and node and I'm trying to build a simple app to retrieve stock prices.
I'm able to reach my server route that I want but I'm getting a FetchError: invalid json response body from my server, what does this mean? How should I properly fetch an external api in my express route and send that data as a response?
import React, { Component } from 'react';
import logo from './logo.svg';
import './App.css';
class App extends Component {
state = {
response: '',
symbol: '',
};
handleSubmit = async e => {
e.preventDefault();
let apiURL = `/stocks/${ this.state.symbol }/price`
fetch(apiURL)
.then(res => res.json())
.then( (result) => {
this.setState({
response: result
})
})
};
render() {
return (
<div className="App">
<header className="App-header">
<img src={logo} className="App-logo" alt="logo" />
</header>
<form onSubmit={this.handleSubmit}>
<input
type="text"
value={this.state.symbol}
onChange={e => this.setState({ symbol: e.target.value })}
/>
<button type="submit">Submit</button>
</form>
<p>{this.state.response}</p>
</div>
);
}
}
export default App;
server.js
const express = require('express')
const path = require('path')
const bodyParser = require('body-parser')
const fetch = require('node-fetch');
const app = express()
const port = process.env.PORT || 5000
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({ extended: true }))
// API routes
app.get('/stocks/:symbol/price', (req, res) => {
const token = 'pk_5f69bda1e3074237a9d2e844a3dafbff'
const symbol = req.params.symbol
const apiURL = `https://sandbox.iexapis.com/stable/stock/${symbol}/price?token=${token}`
fetch(apiURL)
.then(res => res.json())
.then(data => {
res.send({ data })
})
})
app.listen(port, () => console.log(`Listening on port ${port}`))
package.json
{
"name": "client",
"version": "0.1.0",
"private": true,
"dependencies": {
"axios": "^0.19.0",
"body-parser": "^1.18.3",
"express": "^4.16.4",
"node-fetch": "^2.6.0",
"react": "^16.9.0",
"react-dom": "^16.9.0",
"react-scripts": "0.9.x"
},
"devDependencies": {
"concurrently": "^4.0.1",
"nodemon": "^1.9.2",
"ws": "3.3.2"
},
"scripts": {
"start": "react-scripts start",
"build": "react-scripts build",
"test": "react-scripts test --env=jsdom",
"eject": "react-scripts eject",
"client": "yarn start",
"server": "nodemon server.js",
"dev": "concurrently --kill-others-on-fail \"yarn server\" \"yarn client\""
},
"proxy": "http://localhost:5000/"
}