One of the conditions for the offer is, that it has to be redeemed within 3 months. June is 4 months ago.
The offer is for Apple TV+ (note the Plus), which is not “everything in the Apple TV app”.
With the Apple TV app on your Mac, you can access:
- iTunes Store movies and TV shows (buy or rent);
- Apple TV+ channel featuring Apple Originals, by subscription; ← Just this channel has the offer.
- other premium Apple TV app Channels, each by subscription.
- playback of local media files (i.e. files on your Mac);
- playback of Home Sharing media files (i.e. to/from computers on your home network).