How to watch Apple TV+ on Mac using Mojave

We have one free year of Apple TV+. Our 3rd generation Apple TV has only worked once with Apple TV+ and that was only after a full reset. It worked after the reset and then after the ATV was turned off, upon turning it back on, Apple TV+ just sits and spins.

So I'm trying on my Mac. According to the information about Apple TV+ on the Apple website, there's supposed to be an Apple TV app. However, I can't find it.

My Mac is updated with the latest Mojave updates and is working fine, but looking in the App Store, there isn't an Apple TV app listed.

How do I get the Apple TV app that is mentioned in Apple's literature?

Thanks