Webpack Config Found No Entry Configured

I am having some trouble with using Webpack on my Ruby on Rails project. I am following the tutorial series on WebCrunch (https://web-crunch.com/lets-build-with-ruby-on-rails-project-management-app/). When I try run webpack-dev-server I receive the following error:

No configuration file found and no entry configured via CLI option. When using the CLI you need to provide at least two arguments: entry and output. A configuration file could be named 'webpack.config.js' in the current directory. Use --help to display the CLI options.

So instead I run webpack-dev-server --config config/webpacker.yml and I receive this error:

Configuration file found but no entry configured. Use --help to display the CLI options.

Attached is my webpacker.yml file and also my package.json. I am also going to attach a screenshot of the project directory.

webpacker.yml

# Note: You must restart bin/webpack-dev-server for changes to take effect

default: &default
  source_path: app/javascript
  source_entry_path: packs
  public_output_path: packs
  cache_path: tmp/cache/webpacker

  # Additional paths webpack should lookup modules
  # ['app/assets', 'engine/foo/app/assets']
  resolved_paths: []

  # Reload manifest.json on all requests so we reload latest compiled packs
  cache_manifest: false

  extensions:
    - .coffee
    - .erb
    - .js
    - .jsx
    - .ts
    - .vue
    - .sass
    - .scss
    - .css
    - .png
    - .svg
    - .gif
    - .jpeg
    - .jpg

development:
  <<: *default
  compile: true

  # Reference: https://webpack.js.org/configuration/dev-server/
  dev_server:
    https: false
    host: localhost
    port: 3035
    public: localhost:3035
    hmr: false
    # Inline should be set to true if using HMR
    inline: true
    overlay: true
    compress: true
    disable_host_check: true
    use_local_ip: false
    quiet: false
    headers:
      'Access-Control-Allow-Origin': '*'
    watch_options:
      ignored: /node_modules/


test:
  <<: *default
  compile: true

  # Compile test packs to a separate directory
  public_output_path: packs-test

production:
  <<: *default

  # Production depends on precompilation of packs prior to booting for performance.
  compile: false

  # Cache manifest.json for performance
  cache_manifest: true

package.json

{
  "name": "Groupie",
  "private": true,
  "dependencies": {
    "@rails/webpacker": "^3.2.0",
    "coffeescript": "1.12.7",
    "require-yaml": "0.0.1",
    "rvm": "^0.3.2",
    "vue": "^2.6.10",
    "vue-loader": "^15.7.0",
    "vue-template-compiler": "^2.6.10",
    "webpack": "^2.2.0",
    "webpack-dev-server": "^2.10.1"
  },
  "devDependencies": {}
}