Ionic 4 - ion-input underline

On my project Ionic 4 Angular 7 i’ve a setting page with this code:

<ion-content padding class="tab4-content">
  <ion-list>
    <ion-item>
      <ion-label>{{ 'VERSION' | translate }}:</ion-label>
      <ion-label class="aligned-right">{{ version }}</ion-label>
    </ion-item>
  </ion-list>
  <ion-list>
    <ion-item>
      <ion-label>{{ 'GPS' | translate }}</ion-label>
      <ion-toggle [disabled]="GPSshouldDisable" checked="false"></ion-toggle>
    </ion-item>
    <ion-item>
      <ion-label>{{ 'GPSE' | translate }}</ion-label>
      <ion-toggle [disabled]="GPSEshouldDisable" checked="false"></ion-toggle>
    </ion-item>  
  </ion-list>
</ion-content>

this the result:

items-underline.png812×686 36.3 KB

How can i change settings described on screenshot ?
Thanks