Hi ShehzadQ, 

Thanks for posting here! Let me share something about invoices.

The tax info will automatically show on the total section of the invoice. We're unable to do it by line item if that's what you mean. You'll want to check this article for more details on how to customise sales forms: Customise invoices, estimates, and sales receipts in QuickBooks Online.

I'll be here if you need anything else. Stay safe!