Inject owner into class

classes.my-class\.js

import { setOwner } from '@ember/application';
import { inject as service } from '@ember/service';

export default class MyClass {
  @service myService;
  
  constructor(owner) {
    setOwner(this, owner);
    this.appName = this.myService.appName;
  }
}

controllers.application\.js

import Controller from '@ember/controller';
import { getOwner } from '@ember/application';
import { tracked } from '@glimmer/tracking';
import MyClass from '../classes/my-class';

export default class ApplicationController extends Controller {
  @tracked appName;

  constructor() {
    super(...arguments);
    
    this.appName = new MyClass(getOwner(this) ).appName;
  }
}

services.my-service\.js

import Service from '@ember/service';

export default class MyService extends Service {
  appName = 'Ember Twiddle';
}

templates.application\.hbs

<h1>Welcome to {{this.appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>

twiddle\.json

{
  "version": "0.17.2",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": true,
    "_APPLICATION_TEMPLATE_WRAPPER": false,
    "_JQUERY_INTEGRATION": false
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}