Either have a jailbroken ipad, iOS 16.5.1 or earlier, or buy one of the devices that enable it. Search Amazon.
Edit: actually, I'm not sure if the 2025 allows wired adapters since it has wireless built in.
I don't think apple has an actual carplay app in their apple store. Carplay is part of apple phones' OS. But it's not included in their tablets, so you have no option to just add it as an app.
On my Samsung (Android OS) tablet, I simply installed Android Auto from the google play store.