We're unable to provide a file of all of the receipts you've uploaded for tax purposes, but you of course have access to all the information that's available in the app, in your account!
Receipts, for offers that require them, stay live in the app for a year, and you can use that information however you'd like.
We here at Upside always recommend speaking with a tax advisor to ensure that your taxes are done with correct compliance of tax law.