Thanks for getting back here, @Snowman.

Let's make sure that you've selected the correct Report period when running the Sales Tax Liability Report. If all filters are correct and can't still see the Non Taxable Amount column, I suggest reaching out to our technical support team to further investigate the root cause of the issue. To do so, please follow these steps:

1. Go to the Help menu and select Contact Us.
2. From the What can we help you with? field, enter Non-taxable sales not showing on the Sales Tax report.
3. Then, click Continue.
4. Choose either Chat with us or Have us call you. 

Also, you create a Non-Taxable sales report in QuickBooks Online using these steps:

1. Navigate to the Reports menu.
2. From the search field, key in and click Taxable Sales Detail.
3. Hit Customize.
4. Choose the date range in the General dropdown.
5. On the Filter dropdown, check the box for Customer Taxable, and choose Non-Taxable. Check also the Distribution Account box then, pick All Income/Expense Accounts and the Product/Service Taxable box then, choose  Non-Taxable.
6. Select Run report. 

For more info on customizing your report, please visit this link: Customize reports in QuickBooks Online.

Once done, you can memorize the report to save the modification settings on it.

Let me know how this goes and feel free to leave a message in the comment section. I'll be around to help you in running your sales reports in QuickBooks. Take care and have a great day.