Yes, you can. You'll find your Shop & Save Vouchers, e.g., €10 off €50, within the Wallet section of the app.
Vouchers expiring soon will also display on the App Home Screen.
Note: Vouchers may take up to 30 minutes to appear in your App once you earn them, and vouchers you use may take up to 30 minutes to move from the active vouchers section to the Voucher History section.