Redeem Xbox Game Pass promo code without a payment method?

So I got a 7-day trial subscription for the xbox game pass ultimate from Pringles. But if I want to redeem it, it says that I have to specify a payment method because the subscription is automatically renewed, although I have entered in my account that the subscription will not continue automatically. What can I do?

No, as far as I've tried it myself and wrote to Xbox support, it doesn't work. You need to add an alternative payment method. You can then delete them again after deactivating the recurring billing, but well, otherwise there's no other way.