To redeem digital Cumulus vouchers, they must first be activated. Activating them on the app or the web portal loads them onto your digital Cumulus card. They are then automatically applied to your purchases and redeemed the next time you show your digital Cumulus code on the Migros app and it is scanned at checkout.
Two-factor authentication provides greater protection for your Cumulus vouchers on the Migros app. Read here what this means.