I want the GST% to appear in the invoice as well as the GST amount of each item in a separate column.

Hello, asmcomputer-as. 

Welcome to the Community, I'd be happy to help with your questions about GST in QuickBooks Online. 

In order to add GST to the invoice, you'll first need to set it up. The following article includes steps on how to set up GST and adding it to the invoices. 

• Setting up QuickBooks for GST 
• Customise invoice for GST 

For future reference, you can check this article to know more how QuickBooks calculate sales tax: 

• Learn how QuickBooks Online calculates tax 

I'm always at your side if you still need my help. Stay safe!