It's nice to see you here in the Community, @SH611. I can help you change the service item from taxable into non-taxable. 

It is easy to change taxable items into non-taxable items. You can follow the steps below.

1. Go to the Sales menu and select Product and Services. 
2. Click New on the upper right then select Service and fill in necessary information.
3. Scroll down a bit and click on Edit sales tax link.
4. From there, click on "Still don't see what you're looking for?" then scroll down a bit and select Nontaxable.
5. Then, select Done. 

I've also added a screenshot for visual reference. 




In case you need to apply sales tax rates to transactions and sales forms in QuickBooks Online, click here.

If you wish to send an invoice and you need an extra hand, feel free to get back. I'll be glad to assist you. Take care!