App refused to connect (NodeJs & Express) - node.js

Question

I've created an app in the Partners panel, and I followed this documentation (using Nodejs and Express).
I can get the JSON format for the products' object without any problem. However, when I add to the scopes variable "read_price_rules" I get this error message: "express-example-app refused to connect."
Is this issue caused by the app's permissions?
My app can: Read products, variants, and collections.
Here is the index.js file:
const dotenv = require('dotenv').config();
const express = require('express');
const app = express();
const crypto = require('crypto');
const cookie = require('cookie');
const nonce = require('nonce')();
const querystring = require('querystring');
const request = require('request-promise');
const apiKey = process.env.SHOPIFY_API_KEY;
const apiSecret = process.env.SHOPIFY_API_SECRET;
const scopes = 'read_products,read_price_rules';
const forwardingAddress = "https://53b16008.ngrok.io";
app.listen(3000, () => {
console.log('Example app listening on port 3000!');
});
app.get('/shopify', (req, res) => {
const shop = req.query.shop;
if (shop) {
const state = nonce();
const redirectUri = forwardingAddress + '/shopify/callback';
const installUrl = 'https://' + shop + '/admin/oauth/authorize?client_id=' + apiKey + '&scope=' + scopes + '&state=' + state + '&redirect_uri=' + redirectUri;
res.cookie('state', state);
res.redirect(installUrl);
}
else { return res.status(400).send('Missing shop parameter. Please add ?shop=your-development-shop.myshopify.com to your request'); }
});
app.get('/shopify/callback', (req, res) => {
const { shop, hmac, code, state } = req.query;
const stateCookie = cookie.parse(req.headers.cookie).state;
if (state !== stateCookie) { return res.status(403).send('Request origin cannot be verified'); }
if (shop && hmac && code) {
// DONE: Validate request is from Shopify
const map = Object.assign({}, req.query);
delete map['signature'];
delete map['hmac'];
const message = querystring.stringify(map);
const providedHmac = Buffer.from(hmac, 'utf-8');
const generatedHash = Buffer.from(crypto.createHmac('sha256', apiSecret).update(message).digest('hex'), 'utf-8');
let hashEquals = false;
try { hashEquals = crypto.timingSafeEqual(generatedHash, providedHmac) }
catch (e) { hashEquals = false; };
if (!hashEquals) { return res.status(400).send('HMAC validation failed'); }
// DONE: Exchange temporary code for a permanent access token
const accessTokenRequestUrl = 'https://' + shop + '/admin/oauth/access_token';
const accessTokenPayload = {
client_id: apiKey,
client_secret: apiSecret,
code,
};
request.post(accessTokenRequestUrl, { json: accessTokenPayload })
.then((accessTokenResponse) => {
const accessToken = accessTokenResponse.access_token;
// DONE: Use access token to make API call to 'shop' endpoint
const shopRequestUrl = 'https://' + shop + '/admin/api/2019-04/discount_codes/lookup.json?code=20OFF';
const shopRequestHeaders = { 'X-Shopify-Access-Token': accessToken, };
request.get(shopRequestUrl, { headers: shopRequestHeaders })
.then((shopResponse) => {
res.status(200).end(shopResponse);
})
.catch((error) => {
res.status(error.statusCode).send(error.error.error_description);
});
})
.catch((error) => {
res.status(error.statusCode).send(error.error.error_description);
});
} else {
res.status(400).send('Required parameters missing');
}
});

Answer 1

I Just had to reinstall the app after adding an extra scope in the index.js file.