Webpack Dev Server conexão recusada

Boa tarde,

Fiz as modificações na aplicação e instalei e configurei o webpack dev server porem quando acesso a pagina http://localhost:8080/ me é apresentado os seguintes erros no console:

POST http://localhost:3000/negociacoes net::ERR_CONNECTION_REFUSED (anonymous) @ bundle.js:9775 webpack_require @ bundle.js:20 (anonymous) @ bundle.js:707 webpack_require @ bundle.js:20 (anonymous) @ bundle.js:63 (anonymous) @ bundle.js:66

localhost/:1 Uncaught (in promise) TypeError: Failed to fetch Promise.then (async) (anonymous) @ bundle.js:9775 webpack_require @ bundle.js:20 (anonymous) @ bundle.js:707 webpack_require @ bundle.js:20 (anonymous) @ bundle.js:63 (anonymous) @ bundle.js:66

As minhas configurações estão da seguinte forma:

app.js

fetch('http://localhost:3000/negociacoes', config)
    .then(() => console.log('Dado enviado com sucesso'));

webpack.config.js

module.exports = {
    entry: './app-src/app.js',
    output: {
        filename: 'bundle.js',
        path: path.resolve(__dirname,'dist'),
        publicPath: 'dist'
    },
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /node_modules/,
                use: {
                    loader: 'babel-loader'
                }
            }
        ]
    },

    plugins
}

express.js

var express = require('express')
    ,app = express()
    ,routes = require('../app/routes')
    ,path =  require('path')
    ,bodyParser = require('body-parser');

// app.set('clientPath', path.join(__dirname, '../..', 'client'));
// console.log(app.get('clientPath'));
// app.use(express.static(app.get('clientPath')));

 app.use(bodyParser.json());

app.use(function(req, res, next) {
  res.header("Access-Control-Allow-Origin", "*");
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
  next();
});