Validation Ionic 4

#1

How to validate filds the input Ionic 4?

<ion-item>
   <ion-label position="floating">Matrícula</ion-label>
       <ion-input type="text" name="name" name="ngModel" [(ngModel)]="this.service.usuario.name" required></ion-input>
        <!-- <mat-error *ngIf="name.invalid && name.touched">
         Fild Name <strong>required!</strong>
        </mat-error> -->
</ion-item>
#2

There are lots of tutorials online, do a Google search.

e.g.