Quickstart Angular code

I am using the Angular SPA quickstart. This sample works just fine. I have two comments. I am trying to move this code to an app of my own and I am getting this error
'fa-icon' is not a known element
This element is referenced in the nav-bar component HTML. I was wondering if someone knew what library or package I needed to install or configure to get this element to be recognized?
The second question is in my app module I am importing like:

import { HighlightModule } from 'ngx-highlightjs';
. . .
languages: hljsLanguages
I have a squiggly red line that tells me ‘forRoot’ does not exist on HighlightModule.
I realize that these questions don’t have to do with Auth0 but I am not able to translate the quickstarts to my code. Please help.
Thank you.

A semi-educated guess: fa-icon likely comes from the Font Awesome system. I’m not sure what package that means in the Angular world but try searching for that.

I’m afraid I don’t know Angular so I can’y comment on the forRoot issue.

Thank you. That was my guess as well. I imported the angular module like:

import { FontAwesomeModule } from '@fortawesome/angular-fontawesome';
. . . .
. . . .
  imports: [
. . . . 

And I still get the same error.

I have the forRoot lines commented out for now. Hopefully it is not there.