How to connect our iPad to APPLE TV and to smartTV

If you are referring to an actual Apple TV box, you need to connect the Apple TV box to your smart TV via an HDMI cable

Then set the TV for the correct HDMI connection port.

Then use Apple AirPlay 2 to connect both Apple TV box and iPad to mirror the content from your Apple TV box to your TV.

AirPlay - Apple

If you own an Samsung, Sony, LG or Vizio smart TV, you may even not need the Apple TV box and simply connect your iPad directly to your smart TV via AirPlay 2

You maybe even be able to directly AirPlay 2 anything on your iPad ( even the iPad's own Apple TV app ) to your smart TV, IF it is AirPlay 2 compatible.

Best of Luck to You!

What year and model iPad do you have/own?

What iOS/iPadOS version is this iPad,currently, running?