how to get apps from ipad to apple tv?

What is your model Apple TV? Identify your Apple TV model - Apple Support

The App Store on Apple TV (4th generation or later) has its own apps. Developers have to create an app for Apple TV to have it be available there. Some developers choose to make their apps for iPhone and iPad only.

Apps that you get on iPad can automatically be installed on Apple TV, if it exists there, if you activate the setting for that.

You can't do that.

App Store app is available on an TV HD or TV 4K models directly.