
    <nz-back-top [nzTemplate]="tpl" [nzVisibilityHeight]="100" (nzClick)="notify()">
      <ng-template #tpl>
        <div class="ant-back-top-inner">UP</div>
      </ng-template>
    </nz-back-top>
    Scroll down to see the bottom-right
    <strong>blue</strong>
    button.
  