How do I get MLB tv on Apple tv?

If it's a 4th Generation (Apple TV HD) or Apple TV 4K, open the App Store App and download the MLB app from there.

link-> https://apps.apple.com/us/app/mlb/id493619333#?platform=appleTV

If it's a third generation or earlier Apple TV, then you cannot. MLB is no longer supported on those older models.

If you own an Apple TV then you do as I explained above.

If you just have the Apple TV App on your home TV, then there is no MLB channel for the Apple TV app, so unless you own a compatible device with MLB's apps, you cannot.

See here: https://www.mlb.com/apps/mlb-app