Prevent standalone build from executing without custom launcher

I'm currently creating my own game launcher which collates all the games that we've been making and does what every other game launcher does like update, download, etc. I wanted to add a feature into the standalone that it would show an error similar to what League of Legends does if you try to execute it without the launcher.

Is that possible? I don't know if there's a built-in feature in Unity about this since I don't see any posts about it

 

I guess the standalone launcher could run a local server and then your game tries to connect to it.