Invalid symbol error with binance api request

Question

I'm currently working on react app which compare crypto buy price from wallet and actual price and return profit/loss. I created a backend server to call the binance endpoint and here is the code:

import fetch from 'node-fetch';
import crypto from 'crypto';
import { HttpError } from 'http-errors';
import express from 'express';

const app = express();
const port = 9000;
app.use(express.json());

const process_env_API_URL = 'https://api.binance.com';
const process_env_API_SKEY =
    '';
const process_env_API_PKEY =
    '';

app.get('/', async (req, res) => {
    const endPoint2 = '/api/v3/allOrders';
    const dataQueryString = 'timestamp=' + Date.now();
    const signature = crypto
        .createHmac('sha256', process_env_API_SKEY)
        .update(dataQueryString)
        .digest('hex');

    const symbol = 'BTCUSDT';

    const url = process_env_API_URL + endPoint2 + '?' + 'symbol='+ 'symbol' + '&';
    dataQueryString + '&signature=' + signature;
    console.log(url);
let currentBalances;

try {
    currentBalances = await fetch(url, {
        headers: { 'X-MBX-APIKEY': process_env_API_PKEY },
    })
        .then((res) => res.json())
        .then((data) => console.log(data));
} catch (err) {
    return next(new HttpError('API Error...', 500));
}


app.listen(port, () => {
    console.log(`app listening on port ${port}`);
});

The problem is with symbol param. I don't know where put it (in header or where in query).I always get error about invalid symbol, or not allowed characters when I use '=' in query. I tried all options and I don't know how to fix it. On this website when I put params I get correct response : https://syncwith.com/api/binance/get/api-v3-myTrades. Thank you for all help!