Legacy Apple TV won’t log into Apple ID
Generate verification code to log in legacy Apple TV that won’t recognise 2FA
Users are supposed to be able to sign in for the iTunes Store services, but unfortunately not anymore for iCloud services. The latter is no longer supported due to changes in iCloud, for which no system software update is available for these older models. Also see: discussions.apple.com/thread/255664587.
It seems that manually requesting a new verification code has been made difficult or impossible on the latest versions system software for iPhone, iPad, and Mac. It was a separate option on older system software. 🤷♂️