How can I get a report of the nontaxable sales

Thanks for getting in touch with the Community, burque.
 

If you need a list of all customers with non-taxable sales, you can run a Non-Taxable sales report.
 

Here's how:
 

1. In your left navigation bar, go to Reports.
2. In the search field, type in "Taxable Sales Detail", then click Taxable Sales Detail from your drop-down list.
3. Hit Customize and specify a date range in the General ▼ drop-down.
4. Use your Filter ▼ drop-down and set Customer Taxabale to list all customers with non-taxable sales.
5. Set the Distribution Account as All Income/Expense Accounts from your ▼ drop-down. This hides the A/R Source line in the report.
6. Specify Non-Taxable from your Product/Service Taxable ▼ drop-down.
7. Select Run report.

I've also included a detailed resource about working with Non-Taxable sales reports which may come in handy moving forward: Create a Non-Taxable sales report

Please don't hesitate to send a reply if there's additional questions. Have an awesome Monday!