[minimaul]

There's actually a solution for that: https://support.apple.com/en-gb/HT204915

> What if I use two-factor authentication on a device running older software?

> If you use two-factor authentication with devices running older OS versions – such as an Apple TV (2nd or 3rd generation) – you may be asked to add your six-digit verification code to the end of your password when signing in. Get your verification code from a trusted device running iOS 9 and later or OS X El Capitan and later, or have it sent to your trusted phone number. Then type your password followed by the six-digit verification code directly into the password field.

[Nexxxeh]

This weirdly works in some other places. Iirc one of the Amazon's seller login pages accepts the 2FA code appended to the password to avoid having to go through another page.