why webpack output is always main.js?

I have project with this structure:

my-app/
├─ node_modules/
├─ dist/   
├─ src/
│  ├─ index.css
│  ├─ index.js
│  ├─ index.html
├─ package.json
├─ webpack.config.js

My webpack.js is:

const { Module } = require("webpack");
Module.exports = {
    entry: './src/index.js',
    output: {
        filename: 'bundle.js',
        path: __dirname + '/dist',
    }
}

When I run the command npx webpack or npm run build, the output file is always saved as dist/main.js instead of dist/bundle.js

Any ideas of what I'am doing wrong?