Module parse failed: Unexpected token vanilla js

I have this app that im building.

https://jsfiddle.net/wvpysbnd/

vanilla js and bootstrap

webpack.config.js

const path = require('path')

module.exports ={
    entry: './src/index.js',
    output: {
        filename: 'main.js',
        path: path.resolve(__dirname, 'dist'),
    }
};

package.json

{
  "name": "todolist",
  "version": "1.0.0",
  "description": "",
  "private": true,
  "main": "main.js",
  "dependencies": {
    "bootstrap": "^4.4.1"
  },
  "devDependencies": {
    "webpack": "^4.41.5",
    "webpack-cli": "^3.3.10"
  },
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC"
}

I'm getting this error:

ERROR in ./src/index.js 28:26
Module parse failed: Unexpected token (28:26)
You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders
| 
| 
>     static changeActivity = () =>{
|         activityPage.addEventListener('click', (e) =>{
|             e.preventDefault();

Even if I delete those lines, webpack seems to be stuck there.