How does one create an export invoice under LUT with 0% gst?

Allow me to help with your question about creating invoices with zero GST, nirajpande-gmail.

According to section 16 of the IGST Act, the export of goods and services is treated as a zero-rated supply. This means that the GST would not apply to the export of any kind of goods or services. Here's an article that talks about this for more details: How Do I Apply IGST on My Invoices?.

When creating an invoice for exported products, select Exempt GST (0%) in the drop-down list under the Tax column. 

Transactions with Exempt GSTs will be reported under Section -6 of your GSTR-1 Summary and Detailed report. It lists all transactions with GST registration type as Overseas or Deemed Exports. Here's an article as a reference: Know More About GSTR-1 Summary and Detailed Reports in QuickBooks.

I want to share these GST-related articles as well in case you might need them when paying and filing your taxes:

• Manage GST Payments in QuickBooks Online 
• GSTR-1 Filing 

Don't hesitate to tag me in your reply or post more questions in the forum if you need anything else.