I get the error Cannot find module 'HelloWorld'?

Question

Node.js

Good afternoon,
In a project using NodeJS, VueJS, ExpressJS, the error Cannot find module 'HelloWorld' is thrown, I can not understand why.
Here is the code itself:

package.json

{
  "name": "vue_node",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "node index.js"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.16.2",
    "express-vue": "^4.0.13",
    "sqlite3": "^3.1.13",
    "vue": "^2.3.4"
  }
}

index.js

const express = require('express');
const expressVue = require('express-vue');
const path = require('path');

const app = express();

app.use(expressVue.init({
  rootPath: path.join(__dirname, 'app')
}));

app.set('view engine', 'vue');

app.set('views', path.join(__dirname, 'app'));

app.set('vue', {
  componentsDir: path.join(__dirname, 'app/components')
});

app.use(express.static(path.join(__dirname, 'assets')))

app.get('/', (req, res) => {
  res.renderVue('App');
});


app.listen(3000, () => {
  console.log('Server started on port 3000')
});

app.vue

<template>
  <div id="app">
    <HelloWorld />
  </div>
</template>

<script>
import HelloWorld from 'HelloWorld'

export default {
  name: 'app',
  components: {
    HelloWorld
  }
}
</script>

<style>
</style>

HelloWorld.vue

<template>
  <div>
    <h1>Hello World</h1>
  </div>
</template>

<script>
export default {
  name: 'HelloWorld'
}
</script>

<style>
</style>

Folder structure

Error text:

{ Error: Cannot find module 'HelloWorld'
    at Function.Module._resolveFilename (module.js:536:15)
    at Function.Module._load (module.js:466:25)
    at Module.require (module.js:579:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (App:7:19)
    at Module._compile (module.js:635:30)
    at d:\Projects\Javascript\vue_node\node_modules\express-vue-renderer\lib\utils\require.js:239:15
    at new Promise (<anonymous>)
    at Object.requireFromString (d:\Projects\Javascript\vue_node\node_modules\express-vue-renderer\lib\utils\require.js:171:12)
    at d:\Projects\Javascript\vue_node\node_modules\express-vue-renderer\lib\parser\script.js:69:23 code: 'MODULE_NOT_FOUND' }