Ionic clear button not working properly (ionic 5)

Ionic Framework
1

I am trying to make a button transparent, it supposedly looks like this

image

instead, it looks like this. With the gray background behind the icon

image

this is the html code

<button ion-button clear [routerLink]="['/edit-appointment/', booking.$key]">
          <ion-icon name="create" style="zoom:2.0"></ion-icon>
</button>
<button ion-button clear (click)="deleteBooking(booking.$key)">
          <ion-icon name="trash" style="zoom:2.0"></ion-icon>
</button>

Does anyone know how to make the icon clear?

2

Buttons do not work like this anymore (as part of Ionic v4).

Please look at the Button docs

3 
<ion-button fill="clear" [routerLink]="['/edit-appointment/', booking.$key]">
          <ion-icon slot="icon-only" name="create" style="zoom:2.0"></ion-icon>
</ion-button>
<ion-button  fill="clear"  (click)="deleteBooking(booking.$key)">
          <ion-icon slot="icon-only" name="trash" style="zoom:2.0"></ion-icon>
</ion-button>