Please check the instructions below:
On the mobile app:
1) Tap on Portfolio.
2) On the next page, scroll down and tap on Transaction history.
3) After that, proceed to tap on Export.
4) Another page will appear and you may select either Tax report (PDF) or CSV file. After you've chosen which document you wish to receive you maybe tap on Export.
On the Web app:
Please go to your transactions page under your account. There you can filter a specific coin or choose to display all coins. Then you can click on the Export button at the right of the page to export your transactions as a document.