OpenUI Content field not registering

import { Component, OnInit } from '@angular/core';
import UiExtension from "@bloomreach/ui-extension";

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {
  public title = '';
  public isAuthenticated: boolean;


  async ngOnInit() {
    this.isAuthenticated = true;
     this.load();
   }

  load() {
    UiExtension.register().then((ui) => {
       console.log( "load 1"+ JSON.stringify(ui))
    });
  }
}

ERROR Error: Uncaught (in promise): TypeError: _bloomreach_ui_extension__WEBPACK_IMPORTED_MODULE_5___default.a.register is not a function
TypeError: _bloomreach_ui_extension__WEBPACK_IMPORTED_MODULE_5___default.a.register is not a function