How do I gget the Apple app on my Samsung TV

What model of Samsung TV is it?

Check here for supported models: https://www.apple.com/apple-tv-app/devices/

If it is supported, you may need to update your TV’s software and/or download the App from the Samsung App store: https://www.samsung.com/us/support/answer/ANS00082624/

Only if you have the supported TV set.

Read here => Choose your Smart TV manufacturer - Apple Support