zgo/src/app/show-error/show-error.component.html

<div>
  <div>{{ data }}</div>
  <div class="dismiss" test-selector="aaaa">
    <button mat-icon-button (click)="sbRef.dismiss()">
      <mat-icon>Dismiss</mat-icon>AAAA
    </button>
  </div>
</div>