You've come to the right place, @userahmedsobhi474.
I can guide you in creating a tax code so you can apply it to invoices. Here's how:
Now, you can create an invoice and add a VAT code to it. You can read through this article for more detailed instructions in setting up VAT in your account: How do I set up sales GST/VAT rates and use them on forms? (International QBO).
Also, I've added these articles to help you manage VAT in QuickBooks:
Get back to us here if you have other questions about applying VAT to your invoices and other sales form. I'm always here to help.