To Update iPhone / iPad, follow these steps:
Manually Install Updates
Plug your device into power and connect to the internet with Wi-Fi.
Go to Settings > General, then tap Software Update.
Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now
Set Up Automatic Updates
Go to Settings > General > Software Update.
Tap Automatic Updates, then turn on Download iOS Updates.
Turn on Install iOS Updates. Your device will automatically update to the latest version of iOS or iPadOS. Some updates might need to be installed manually
See this Apple Help Guide for additional help or instructions.
Last Updated: October 6, 2021