El proyecto está basado en Angular 13.

Añadido enrutamiento al proyecto. app-routing.module.ts

 import { NgModule } from '@angular/core'; import {RouterModule, Routes} from "@angular/router"; import {HomePageComponent} from "./home-page/home-page.component"; const appRoutes: Routes =[ { path: '', component: HomePageComponent} ]; @NgModule({ imports: [RouterModule.forRoot(appRoutes)], exports: [RouterModule] }) export class AppRoutingModule { }

agregó AppRoutingModule al archivo app.module.ts

 import { NgModule } from '@angular/core'; import { BrowserModule } from '@angular/platform-browser'; import { AppComponent } from './app.component'; import {ModalModule} from "ngb-modal"; import {FormsModule} from "@angular/forms"; import { HomePageComponent } from './home-page/home-page.component'; import {AppRoutingModule} from "./app-routing.module"; @NgModule({ imports: [ BrowserModule, FormsModule, AppRoutingModule ], declarations: [ AppComponent, HomePageComponent ], providers: [], bootstrap: [AppComponent] }) export class AppModule { }

pero si trato de agregar al archivo app.component.html

 <router-outlet></router-outlet>

IDEA arroja un error

 Cannot resolve symbol 'router-outlet'

Pero si abro otro proyecto con enrutamiento en el mismo IDE, no hay tal error.