how to enter two factor authentication on apple tv1

If you really have an Apple TV (1st generation), the big 7.7" silver-white slab, then it will not connect to the iTunes Store anymore. Signing in will fail. That service ended 2.5 years ago for that model.

Identify your Apple TV model - Apple Support

Hello Haywood2020.

Thanks for reaching out to Apple Support Communities. We see that you have an Apple TV 1st generation and need help with signing in using two-factor authentication. We will be glad to assist.

Please see the steps below from the following resource:Two-factor authentication for Apple ID

"If you use two-factor authentication with devices running older OS versions—like an Apple TV (2nd or 3rd generation)—you 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."

Cheers.