@Component(...)
export Class AutocompleteComponent {
  ...
}

@NgModule({
  imports: [
    CommonModule,
    ...
  ],
  declarations: [
    AutocompleteComponent
  ],
  exports: [AutocompleteComponent],
})
export Class AutocompleteModule {
  ...
}

ng generate component standalone --standalone

@Component({
  selector: 'app-standalone',
  standalone: true,
  imports: [CommonModule], // <-- all imports goes here
  templateUrl: './standalone.component.html',
  styleUrls: ['./standalone.component.scss']
})
export class StandaloneComponent implements OnInit {
  ...
}

// app.module.ts
@NgModule({
  declarations: [
    AppComponent,
    ...
  ],
  bootstrap: [AppComponent],
  imports: [
    BrowserModule,
    AppRoutingModule,
    BrowserAnimationsModule,
    ...
  ],
  providers: [],
})
export class AppModule { }

// main.ts
platformBrowserDynamic()
  .bootstrapModule(AppModule)
  .catch(err => console.error(err));

@NgModule({
  declarations: [AppComponent],
  bootstrap:    [AppComponent],
  imports: [
    BrowserModule,
    AppRoutingModule,
    BrowserAnimationsModule,
  ],
  providers: [],
})
export class AppModule { }

@Component({
  selector: 'app-root',
  standalone: true, // <- add standalone
  imports: [], // <- and imports array
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss']
})
export class AppComponent {
}

bootstrapApplication(
  AppComponent, 
  {
    providers: [
      importProvidersFrom([
        BrowserModule,
        AppRoutingModule,
        BrowserAnimationsModule,
      ])
    ]
  }
)

const routes = [
  {
    path: 'standalone',
    component: StandaloneComponent,
  },
  ...
];

const routes = [
  {
    path: 'standalone-lazy',
    loadComponent: () => import('./components/standalone-lazy.component')
    	.then(s => s.StandaloneLazyComponent),
  },
]

const routes = [{
  path: 'standalone-childrens',
  loadComponent: () => import('./components/standalone-childrens.component')
    .then(s => s.StandaloneChildrenComponent),
  children: [
    {
      path: 'child-firstchild',
      component: import('./components/standalone-first-child.component')
      .then(s => s.FirstChildComponent)
    },
    {
      path: 'child-firstchild',
      component: import('./components/standalone-first-child.component')
      .then(s => s.FirstChildComponent)
    },
  ]
}]

importProvidersFrom([
  BrowserModule,
  RouterModule.forRoot(routes),
  BrowserAnimationsModule,
  HttpClientModule,
]),

bootstrapApplication(AppComponent)
  .then((ref) => {
    const wc = createCustomElement(
      HelloComponent, {
        injector: ref['injector'],
      }
    );
  });

// get a hand on the environment injector
const envInjector = await createRootEnvironment();

// create a constructor of a custom element
const NgElementCtor = createCustomElement(TestStandaloneCmp, {
  injector: envInjector
});

// register in a browser
customElements.define('test-standalone-cmp', NgElementCtor);