Add class only to the clicked item

Component #1

(click)="setActive()"

@Output() activate = new EventEmitter<void>();

setActive() {
  if (!this.isDisabled) {
    this.activate.emit();
  }
}

Component #2

<your-component
  *ngFor="let item of menuItem; let i = index"
  [isActive]="i === activeItemIndex"
  (activate)="onActivate(i)"
></your-component>

activeItemIndex: number | null = null;

onActivate(index: number) {
  this.activeItemIndex = index;
}