Explicación: Servicios http
Completion requirements
8. POST (crear)
8.2. Componente de formulario
ng g c pages/post-form --standalone
Y lo añadimos a la ruta (posts/new debe ir antes que posts/:id)
src/app/app.routes.ts
import { PostFormComponent } from './pages/post-form/post-form.component';
export const routes: Routes = [
{ path: '', redirectTo: 'posts', pathMatch: 'full' },
{ path: 'posts', component: PostsListComponent },
{ path: 'posts/new', component: PostFormComponent }, // Aquí
{ path: 'posts/:id', component: PostDetailComponent },
{ path: '**', redirectTo: 'posts' },
];