Videogular error 'vg-player' is not a known element

Question

I'm trying to play audio with videogular2 but have this error. 'vg-player' is not a known element. I searched and I think the code is fine. Any idea?

My code is as follows:

import { VgCoreModule } from 'videogular2/compiled/core';
import { VgControlsModule } from 'videogular2/compiled/controls';
import { VgOverlayPlayModule } from 'videogular2/compiled/overlay-play';
import { VgBufferingModule } from 'videogular2/compiled/buffering';
import { VgAPI } from 'videogular2/compiled/core';

@NgModule({
  imports: [
    VgCoreModule,
    VgControlsModule,
    VgOverlayPlayModule,
    VgBufferingModule
  ],
  providers: [VgAPI]
})

Html code is simple.

<vg-player>
  <video id="audio" preload="auto" controls>
  <source type="application/x-mpegURL" src="">
  </video>
</vg-player>

Thank you.