Netflix payment method?

I got Netflix so the first 30 days it doesn't cost anything but after that you have to pay either 9.99 euro, 11.99 euro or 15.99 euro per month (depending on what you choose) , 99 euro decided on Monday, in 3 days I have to pay this for the first time. My problem is that when I got this 30-day free version, I didn't specify a payment method. There was the possibility of entering his billing address, i.e. The place of residence + the IBAN. I chose that, now I just don't know whether the IBAN was accepted, because the message keeps coming up that Netflix has a problem and I should try another payment method. But that's the only method I can do. Because I have neither a MasterCard nor an American Express Card but a Sparkasse card. Can you help me please.

Go to the gas station and buy a Netflix card.

Did NF complain from the start?

From a NF point of view, a direct debit is not safe, only a KK offers the security that you will get your money.

Actually, there shouldn't have been a contract because you chose direct debit.

Can I see somewhere which payment method I have specified, whether it now has my IBAN

What do you think? I mean I could still cancel my free subscription, but I still want to have Netflix, now I just don't know whether you have my bank details or not

If you have not received a confirmation, but only ever one problem report, then I assume that one has to be found and the IBAN is not accepted. Can't you call NF?