Integrating Quill text editor in an Angular application

I am learning how to create blogging websites. I tried a simple example first. But the text editor is not showing up on my screen. I installed Quill with npm install --save quill@1.3.6 ngx-quill command. My app.component.html is very simple.

<nav class="navbar navbar-expand-lg navbar-light bg-light">
  <a class="navbar-brand ml-auto mr-auto" href="#">Quill JS Editor with Angular</a>
</nav>

<div class="container">
  <div class="row pt-5">
    <div class="col-md-8">
      <form [formGroup]="editorForm" (ngSubmit)="onSubmit()">
        <div class="form-group">
          <label for="editor">
            <h3>Editor</h3>
          </label>
          <quill-editor></quill-editor>
        </div>
      </form>
    </div>
    <div class="col-md-4 bg-light p-4">
      <h3>Output</h3>
      <p class="my-5"></p>
    </div>
  </div>
</div>

Actually it should look like.

I have also imported FormGroup and FormControl from @angular/forms in my app.component.ts which contains the following code.

import { Component, OnInit } from '@angular/core';
import { FormGroup, FormControl } from '@angular/forms';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {
  editorForm: FormGroup;
  ngOnInit() {
    this.editorForm = new FormGroup({
      'editor': new FormControl(null)
    })
  }
}

But I am getting this error.

The entire project is on github. Please tell me what else I am missing in this project.

It means you haven't configured that library properly, particularly you should be importing QuillModule.forRoot() so that all delivered with this library providers are properly initialized.

@NgModule({
  imports: [
    BrowserModule,
    QuillModule.forRoot(),
...

Btw, this is how documentation tells us to do it.