TrueRev sends invoices via the Quickbooks API using the "default" template. Invoices are configured under the settings gear -> Account and settings -> Sales

The first section has a green button called "Customize look and feel"

If you have more than one template, make sure that the one you want to use with TrueRev says "default" like this:

There are several options on how to display the invoice line items - make sure the description, price & quantity, etc are set how you'd like: