Got exactly the same problem today, e.g:
- have two-factor auth.
- tried login to icloud on some old macbook (OSX Lion - 10.7)
- on my iphone i got the code
- but on the macbook there are no input fields - e.g. impossible to enter the code - there is no place where.
More googling and I found this page: https://support.apple.com/en-us/HT204915 where says:
What if I use two-factor authentication on a device running older software?
If you use two-factor authentication with devices running older OS versionsxe2x80x94like an Apple TV (2nd or 3rd generation)xe2x80x94you might 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.
So, in short: if you didn't get the input fields, do the following:
- on the trusted device "Get the verification code" how - see this
- and on the device without input fields enter your password, immediatelly followed by the 6 digit code - e.g. "MyPassord123456"
That's all - it works. :)