lassetr: No apps here. (...)
Problem here is it is not my bank that asks my bank username and password. The one asking is adyen.com. I tried to ask from my bank if they know anything about adyen.com.
Also ask your bank if confirming transactions via phone app would bypass that sort of login request.
Mind you, I'm not arguing here. I wouldn't expect any sort of login request during a transaction and I also wouldn't complete the purchase in that case. But I'm also not familiar with all banks in all countries, so I think it's worth covering all the bases.
As mentioned above, Adyen is a payment processor founded in 2006 and headquartered in the Netherlands. So this is all the more puzzling, because it's not a phishing attempt from some shady unknown site.