Spectrum App

the 2g and 3g appletvs does not have apps they rely on apple server side channels

they are no longer being updated with new stuff I believe

if your spectrum app is not a part of the server side channels you will likely have to purchase a HD(4g) or 4k(5g) model appletv

Getting Started with Spectrum TV on Apple TV - Spectrum Support

Q: Which Apple TV devices support the Spectrum TV app?

A: Apple TV (4th generation) and Apple TV 4K support Spectrum TV.