ngif to show hide button code example
Example 1: hide and show in angular 8
<button (click)="toggleShow()" type="checkbox" >show/hide</button>
<div *ngIf="isShown" class="row container-fluid" id="divshow" >
Div Content
</div>
Example 2: hide button in typescript
var link = document.getElementById('nav-ask');
link.style.display = 'none'; //or
link.style.visibility = 'hidden';