@jdelacueva @EUCommission A couple of years ago, I complained to the portal's assistance service about this very issue, and this is the reply I got.

With SMS now not any more an option, we are really left only with FIDO2 keys.

It is unclear why they can't use established OTP standards compliant with many different platforms, and, if they really, *really* need to re-invent the wheel, why they must release their solution only through US-based platforms that come with debatable ToS.