Watching Apple TV from phone to non smart tv

appletv bypass everything smart about tv's it works the same on a non smart tv or a computer monitor as it does on the smartest tv in the store.

it's unclear what you mean by "How can I use my Apple TV from my phone"

if you mean how you can airplay mirror the iphones content to the screen connected to the appletv

then How to AirPlay video and mirror your device's screen - Apple Support

apart from airplay mirror and airplay audio and being used as remote the iphone and appletv can't use eachother for anything