There is a way to log into Apple TV. I started a new post to fully explain. I'll copy and paste the resolution here. Once two factor authentication is turned on it's permanent. You can't turn it off. To resolve the Apple TV and two factor authentication problem follow this:
The solution that should work for you is something which Apple refers to as 'decorated passwords'.
I found an obscure reference to this in another forum and felt it should be mentioned again for those of us still struggling with forced two factor authentication by Apple.
Enter your password for the first time in Apple TV. This will send the signal to your other Apple device to allow log in and generate the code.
You will then enter the code into Apple TV, which forces you back to log in with Apple ID and password AGAIN. The 2nd time you enter the password, enter the password along with the 6 digit authentication code like this:
If the code you got was "111 111" after the first round, and your password is "password", the second time you enter "password111111" in the password field after you enter your apple username.
The above instructions worked perfectly on the first try. I called Apple support and they confirmed that decorated passwords are the only work around for two factor authentication on older Apple TV products.