Sroll to specific element in list in Ionic 4

In Ionic 3 my app has an alphabetical index for a long list to scroll to the items. I use the following code in html for the list:

  <ion-item-group *ngFor="let group of groupedItems">
      <ion-item-divider id="{{group.letter}}">{{group.letter}}</ion-item-divider>
      <ion-item button *ngFor="let item of group.items" (click)="select(item)" [class.selected]="item.selected === true">
        {{ item.schueler.nachname }} {{ item.schueler.vorname }}

An for the alphabetical Index:

<div id="alphaIndex" #alphaIndex>
  <div class="fast-scroll-container">
    <span *ngFor="let index of indexes">
      <a href="#{{index}}">{{index.toUpperCase()}}</a>

How can I achieve the same in Ionic 4? What is the equivalent syntax for href="…"?