Correct syntax would be navigator.MediaDevices.getUserMedia

The MediaDevices.getUserMedia() method prompts the user for permission to use a media input which produces a MediaStream with tracks containing the requested types of media.

That stream can include, for example, a video track (produced by either a hardware or virtual video source such as a camera, video recording device, screen sharing service, and so forth), an audio track (similarly, produced by a physical or virtual audio source like a microphone, A/D converter, or the like), and possibly other track types.

It returns a Promise that resolves to a MediaStream object. If the user denies permission, or matching media is not available, then the promise is rejected with NotAllowedError or NotFoundError DOMException respectively.

https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia

https://developer.chrome.com/blog/media-devices/#getusermedia

import {
  Component,
  OnInit,
} from '@angular/core';

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

  // Put variables in global scope to make them available to the browser console.
const constraints = window.constraints = {
  audio: false,
  video: true
};
errorString = '';

ngOnInit() {}

handleSuccess(stream) {
  const video = document.querySelector('video');
  const videoTracks = stream.getVideoTracks();
  console.log('Got stream with constraints:', constraints);
  console.log(`Using video device: ${videoTracks[0].label}`);
  window.stream = stream; // make variable available to browser console
  video.srcObject = stream;
}

handleError(error) {
  if (error.name === 'OverconstrainedError') {
    const v = constraints.video;
    errorMsg(`The resolution ${v.width.exact}x${v.height.exact} px is not supported by your device.`);
  } else if (error.name === 'NotAllowedError') {
    errorMsg('Permissions have not been granted to use your camera and ' +
      'microphone, you need to allow the page access to your devices in ' +
      'order for the demo to work.');
  }
  errorMsg(`getUserMedia error: ${error.name}`, error);
}

errorMsg(msg, error) {
  this.errorString = msg;
  if (typeof error !== 'undefined') {
    console.error(error);
  }
}

async init(e) {
  try {
    const stream = await navigator.mediaDevices.getUserMedia(constraints);
    this.handleSuccess(stream);
    e.target.disabled = true;
  } catch (e) {
    this.handleError(e);
  }
}


}

Working example: https://stackblitz.com/edit/media-recorder-ukdruh?file=src%2Fapp%2Fapp.component.ts