Will Apple TV play on 3rd gen apple tv

1. Are you sure its a 3rd generation Apple TV? click here-> Identify your Apple TV model - Apple Support
2. Are you sure its updated to the most recent software? TV Software 7.4 Link-> Update your Apple TV 3rd Generation - Apple Support

All the ways to watch Apple TV+ - Apple Support

Apple TV+ is compatible with Apple TV (3rd generation or later) with up-to-date software.

CaptDT wrote:

Opps, it is 2nd generation, will it work?

In that case, no it won't. Apple TV+ requires a 3rd generation or later Apple TV.