render-modal

components.modal-wrapper\.js

import Component from '@glimmer/component';

export default class extends Component {
}

components.render-modal\.js

import Component from '@glimmer/component';

export default class extends Component {
}

controllers.application\.js

import Controller from '@ember/controller';
import { action } from '@ember/object';

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
  showModal = "contact";
  @action
	toggleModal(currentModal) {
    let showModal = this.showModal === 'contact' ? 'tax' : 'contact';
    
    this.set('showModal', showModal);
  }
  
	@action
  resetModal() {
    this.set('showModal', '');
  }
}

helpers.eq\.js

import { helper } from '@ember/component/helper';

export default helper(function eq(params/*, hash*/) {
  return params[0] === params[1];
});

templates.application\.hbs

<h1>Welcome to {{this.appName}}</h1>
<br>
<br>
{{outlet}}
<button {{on "click" this.toggleModal}}>Toggle Modal</button>
<button {{on "click" this.resetModal}}>Reset Modal</button>
<hr/>
{{#modal-wrapper showModal=this.showModal as |renderModal|}}
	{{#renderModal slot="contact"}}
     Contact Creation
  {{/renderModal}}
  {{#renderModal slot="tax"}}
  	Tax Creation
  {{/renderModal}}
{{/modal-wrapper}}
<br>
<br>

templates.components.modal-wrapper\.hbs

{{#if @showModal}}
  {{yield (component "render-modal" showModal=@showModal)}}
{{/if}}

templates.components.render-modal\.hbs

{{#if (eq @slot @showModal)}}
	{{yield}}
{{/if}}

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "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"
  }
}