If you don’t have a computer

If you don't have a computer, then do this to update your iPhone or iPad:

1. Plug your device into power and connect to the internet with Wi-Fi.
2. Go to Settings > General, then tap Software Update.
3. If you see more than one software update option available, choose the one that you want to install.
4. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.

If no updates are available then you may assume your device is up to date with compatible software.

What do you do about what?

Writing an effective Apple Support Commun… - Apple Community