Jul 8, 2018

If you want to install the beta software, you’ll have to register your device with Apple.

If you want to install the beta software, you'll have to register your device with Apple. 

You can learn how to do this at Apple's Beta Software Program site. Once your iPhone is registered, an available software update will become visible in your Settings. Just make sure you back up your data first, as betas sometimes act in unexpected ways.