Here’s the options with Zwift –
The Ultimate Guide to Training with Xert and Zwift – Xert (baronbiosys.com)
Apple TV doesn’t support viewing a browser page so the only option with Apple TV running Zwift’s app is ZWO export which loses the adaptive signature functions of SMART workouts.
Related thread –
Lesson learned - Difference between Xert workout and workout export to zwift - Support - Xert Community Forum (xertonline.com)