How to use the @nebular/theme.NbGlobalLogicalPosition.TOP_END function in @nebular/theme

title = 'HI there!';
  content = `I'm cool toaster!`;

  types: NbComponentStatus[] = [
    'success',
    'info',
    'warning',
    'danger',
    'primary',
  ];
  positions: string[] = [
    NbGlobalPhysicalPosition.TOP_RIGHT,
    NbGlobalPhysicalPosition.TOP_LEFT,
    NbGlobalPhysicalPosition.BOTTOM_LEFT,
    NbGlobalPhysicalPosition.BOTTOM_RIGHT,
    NbGlobalLogicalPosition.TOP_END,
    NbGlobalLogicalPosition.TOP_START,
    NbGlobalLogicalPosition.BOTTOM_END,
    NbGlobalLogicalPosition.BOTTOM_START,
  ];

  quotes = [
    { title: null, body: 'We rock at Angular' },
    { title: null, body: 'Titles are not always needed' },
    { title: null, body: 'Toastr rock!' },
  ];

  makeToast() {
    this.showToast(this.status, this.title, this.content);
  }

  openRandomToast () {

showToast() {
    this.toastrService.show(
      `Toast number ${this.i}`,
      `Toast with the limit`,
      { limit: 3, position: NbGlobalLogicalPosition.TOP_END });
    this.i++;
  }
}