Hi there, jesguyer. QuickBooks Online includes a way to download your saved mileage trips, which can be helpful when you need a record for tax reporting. The export is downloaded as a CSV file, so you can review or share the details as needed.
You can do this by going to All apps, then Expenses & Bills, and opening Mileage. From there, select the dropdown arrow next to Add trip, then click Download my trips to export your mileage.
If you have additional questions, feel free to reply in this thread.