Free year with new Apple Watch purchase??

I knew the Watch couldn't use it but for some reason thought it qualified. More details confirming your answer, from Apple TV+ - Apple

With purchase 1 year included

Get Apple TV+ for a year when you purchase a new iPhone, iPad, iPod touch, Mac, or Apple TV.2

The Apple TV+ deal applies to devices that can actually use it.

The Apple Watch, an Apple power adapter, an Apple Thunderbolt 3 cable, etc… cannot.

If you are referring to Apple TV+, see the following from About Apple TV+ - Apple Support

I purchased a new Apple device that comes with 1 year free Apple TV+. How do I activate my 1 year Apple TV+ subscription?

Starting November 1, you’ll be able to start your 1 year free Apple TV+ in the Apple TV app. Follow these steps:

More details are in the above link.