Check out example codes for "scroll to top angular". It will help you in understanding the concepts better.

Code Example 1

//inside the app.component.html add (activate):
<router-outlet  (activate)="onActivate($event)"></router-outlet>

//inside app.component.ts, add inside the class of the component:
export class AppComponent {
 
  onActivate(event) {
    window.scroll(0,0);
    //or document.body.scrollTop = 0;
    //or document.querySelector('body').scrollTo(0,0)
    
}
}

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