Open the Bilance app and go to the subscription signup screen.

Tap the "Promo code" button (see the image below).

Enter your promo code and follow the instructions on the screen.

You can use one promo code at a time.

Make sure to enter the promo code before starting a trial or subscription. Otherwise, the promo code won't apply.

Promo codes for extended trial periods are only valid for new users. You can only take advantage of the promo code if you haven't used the Bilance app before.