app-template-wportal.ts

@Component({
  selector: 'my-app',
  template: `
        <ng-template #testTemplate let-name>
          <div>User {{ name }} </div>        
        </ng-template>`,
})
export class AppComponent implements OnInit {
    @ViewChild('testTemplate') testTemplate: TemplateRef<any>;
    private portalHost: DomPortalHost;

    constructor(
     private componentFactoryResolver: ComponentFactoryResolver,
     private injector: Injector,
     private appRef: ApplicationRef,
     private viewContainerRef: ViewContainerRef,
    ) { } 

    ngOnInit() {        
        // Create a portalHost from a DOM element
        this.portalHost = new DomPortalHost(
          document.querySelector('#pageHeader'),
          this.componentFactoryResolver,
          this.appRef,
          this.injector
        );

        // Create a template portal
        const templatePortal = new TemplatePortal(
          this.testTemplate, 
          this.viewContainerRef, 
          {$implicit: 'Bob'},
          );

        // Attach portal to host
        this.portalHost.attach(templatePortal);
    }
}