Adding a button in primeng-treetable paginator

Question

I want to add a download button icon in primeng-treetable paginator bar. But not sure how to customize the paginator of treetable. I found this implementation in prime faces but primeng-treetable has not same type of solution.

Below is the code I have written to add the button but button is coming above the pagintaor bar.

<p-treeTable #tt [columns]="cols" [value]="files" [paginator]="true" [rows]="10">

....... code for showing table data......
//Below code for adding button in paginator.
<ng-template pTemplate="emptymessage">
        <tr>     
            <td [attr.colspan]="cols.length">No data found.</td>
        </tr>
        <tr>     
            <mat-icon (click)="Download()" title="Download Excell">save_alt</mat-icon>
        </tr>
    </ng-template>
</p-treeTable>

If anybody have implemented this then please help. Thanks in Advance !!!