How do I get HBO max to work on my TV

Are you referring to an Apple TV HD or Apple TV 4K “set-top” box? (Apple has a bunch of stuff with names similar to “Apple TV”, confusingly.) If so, connect that to the TV using an HDMI cable, and select the HDMI input port on the TV.

Depending on what device or computer you’re attempting to play the content from, via an HDMI connection, via Thunderbolt, via an Apple TV 4K or Apple TV HD “set-top” box and an HDMI connection, or via AirPlay 2 if your TV has support for that, among other options.

You’ll need to load the HBO app onto whatever you’re playing from, and to log into your HBO credentials if that access doesn’t happen automatically.