how can I get modern view invoices

You can get the modern view for invoices by clicking the Update layout, shihab.

To make the invoice in modern view, here's how:
 

1. Go to +New button.
2. Select Invoice.
3. Click Update layout.
   

If that option is not available to you, please know that this experience with the new layout is not yet accessible in all regions.

You might find this article helpful when managing your customer payments in QuickBooks for future reference: Record invoice payments in QuickBooks Online.

If need further assistance regarding invoices, please don't hesitate to reach out. We're always here to assist you.