How to setup AirPort Express for AirPlay only?

Hello,
Follow the given steps:

Plug the AirPort Express into the wall and wait until it boots up.
Go into your Wi-Fi settings on your iPhone, iPad, or Mac and join the new AirPort network.
Click on the Other Options button.
Select “Add to an existing network.”
Choose your existing Wi-Fi network name from the list. Enter the password.

Apple AirPort Express Setup | Apple AirPort Setup