Glad to have you here in the Community, @dr-bjarnason.

In QuickBooks Online, the mileage report can be pulled up by clicking on the Download Trip button from the Trips page. This will open a report in an Excel file that shows all the trips that you've entered.

To do that, just open the trips page and press on Download Trips. Please see the screenshot attached for your reference:

You may also want to check the reports available for your version in QBO.

I've also added these articles about maintaining mileage, fixing some issues, and other topics. 

• Automatically track mileage in QuickBooks Online
• QuickBooks can do WHAT? Tracking your mileage
• Fix mileage tracking issues in the QuickBooks Online mobile app

Know that you can always get back to me if you need anything else. I'll be around to lend a helping hand. Have a nice day!