Ionic 4 buttons

Side Menu Button

<ion-buttons slot="start">
 <ion-menu-button></ion-menu-button>
</ion-buttons>

Back Button

<ion-buttons slot="start">
          <ion-back-button></ion-back-button>
 </ion-buttons>

End Search button

<ion-buttons slot="end">
 <ion-button (click)="doSomething()">
  <ion-icon slot="icon-only" name="more"></ion-icon>
 </ion-button>
</ion-buttons>