This is super easy. Go to the 'Accounts' section of the app, select '...' to see more and click on 'Statement'.
Select the date range and file format (PDF or Excel) of your statement. Next, tap 'Get statement' and you will be able to see your account history on your screen.
If you would like to download your statement, simply tap the export icon in the top-right corner of the screen and you can download it to your phone.