[vite] http proxy error at

I have an issue when running all my apps, it looks like this

15:49:19 │ web-frontend │ 3:49:19 PM [vite] http proxy error at /?embedded=1&hmac=c2871f2f343c9b90c85dcf7a648380bca74b6dbf0235aa86a4439b6859f039
c7&host=YWRtaW4uc2hvcGlmeS5jb20vc3RvcmUvb21yaS10ZXN0LXN0b3Jl&id_token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwczpcL1wvb21yaS10ZXN0L
XN0b3JlLm15c2hvcGlmeS5jb21cL2FkbWluIiwiZGVzdCI6Imh0dHBzOlwvXC9vbXJpLXRlc3Qtc3RvcmUubXlzaG9waWZ5LmNvbSIsImF1ZCI6IjU5NzJmNTM1MTljZThkMjMwZmU2MzYyO
TQwNTM1YjVjIiwic3ViIjoiOTIwMjc0ODY0NTMiLCJleHAiOjE3Mjg4MjM4MTYsIm5iZiI6MTcyODgyMzc1NiwiaWF0IjoxNzI4ODIzNzU2LCJqdGkiOiI4MWFhN2NmMy0wODkwLTRmODctY
mYwMS0yYTViYjFkODhlZGMiLCJzaWQiOiIzNTRhMzViMy05MTk5LTQzNDUtOGQzMy05MGRmYzdjOGE5OWMiLCJzaWciOiI5NGZmZDdiNzMxYmU5OTUwYTNlNDg1ZGMzODUyNjZlNjRlMTdlY
2NlOWY3OTEyYzg4MTQ0NWM4OGU0ZDMwNWIxIn0.v9tJ7LWfMe1LqCVtjjk9It054JQKkqTE2yUg0TMQ5f4&locale=en&session=b8b0736a4a2cf2bbbf33fc469126ece3639336f6d7d
a116cabc1455b5c22ccad&shop=my-test-store.myshopify.com&timestamp=1728823756:
15:49:19 │ web-frontend │ Error: connect ECONNREFUSED 127.0.0.1:53700

I tried to upgrade my shopify app express package, I tried to play with the proxy definitions in my vite config, nothing worked, If you know a solution much appreciated, Adding my vite.config file here.

import { HmrOptions, defineConfig } from 'vite';
import { dirname } from 'path';
import { fileURLToPath } from 'url';
import react from '@vitejs/plugin-react';
import replaceShopifyApiKey from './plugins/replace-shopify-api-key';

if (
	process.env.npm_lifecycle_event === 'build' &&
	!process.env.CI &&
	!process.env.SHOPIFY_API_KEY
) {
	throw new Error(
		'\n\nThe frontend build will not work without an API key. Set the SHOPIFY_API_KEY environment variable when running the build command, for example:' +
			'\n\nSHOPIFY_API_KEY=<your-api-key> npm run build\n'
	);
}

const proxyOptions = {
	target: `http://127.0.0.1:${process.env.BACKEND_PORT}`,
	changeOrigin: false,
	secure: true,
	ws: false,
};

const host = process.env.HOST ? process.env.HOST.replace(/https?:\/\//, '') : 'localhost';

let hmrConfig: HmrOptions;
if (host === 'localhost') {
	hmrConfig = {
		protocol: 'ws',
		host: 'localhost',
		port: 64999,
		clientPort: 64999,
	};
} else {
	hmrConfig = {
		protocol: 'wss',
		host: host,
		port: Number(process.env.FRONTEND_PORT),
		clientPort: 443,
	};
}

export default defineConfig({
	root: dirname(fileURLToPath(import.meta.url)),
	plugins: [react(), replaceShopifyApiKey()],
	resolve: {
		preserveSymlinks: true,
	},
	server: {
		host: 'localhost',
		port: Number(process.env.FRONTEND_PORT),
		hmr: hmrConfig,
		proxy: {
			'^/(\\?.*)?$': proxyOptions,
			'^/api(/|(\\?.*)?$)': proxyOptions,
		},
	},
});

Start with the supplied vite.config file, especially the server.proxy entries and BACKEND_PORT target, then reproduce the request to /?embedded=1 and the reported ECONNREFUSED error. Done means the affected apps run without this proxy error and the resulting behavior is verified against the reported setup.