My smart tv came with Apple TV built in. But I can’t find the App Store in it to download other apps

Hi, Welcome to Apple's community

don't just get confused your smart tv come with built in apple tv application not with apple tv os so it is just an application where you can buy the apple tv+ subscription and rent or buy the movies available right in the application ( Apple tv is an application and a Apple Tv is a separate device also which can turn your any tv into apple's tv

You don’t have the Apple TV pre-installed on your smart TV, you have the Apple TV app pre-installed. The Apple TV is a piece of hardware that is separate to a TV.

Welcome to the Apple community.

You can only download apps from the App Store to an Apple TV. The Apple TV app is itself an app.

There are channels that you can add to the Apple TV app.

Does your NFHS network provider state that you can watch their programming on an Apple TV or on the Apple TV app?