Complain. Mine wanted that, but after complaining they offered me SMS. If not, I'd have closed my account there. At least here in Spain there are plenty of banks that don't force you to use apps. I also leave bad ratings for banking apps from time to time, and bad comments on X.
In my country there are regulations in effect too that mandate the use of MFA; however, using an application is not the only way to implement MFA, as I said, in Spain banks can use SMS, coordinate cards, etc., and they are all valid MFA methods.
I think what these laws are missing is the obligation for the service (the bank in this case) to provide a MFA device if the user doesn't have one.