1) Open the Settings app.
2) Tap General.
3) Tap Software Update.
4) Tap Download and Install.
TIP: If you get the message, "This update requires a Wi-Fi network connection to download," you will need to connect to a Wi-Fi network before proceeding.
5) If prompted, type your passcode.
NOTE: If you have chosen an alphanumeric passcode, you will need to type it in, and then tap Done in the upper right-hand corner.
6) Review the terms and conditions. If you agree with them, tap Agree.
7) If you agree, tap Agree once again.
8) After the update is downloaded, tap Install Now to continue with the installation.
9) The update will then be verified. When the installation has begun, you will see a screen similar to the one below.
Your device will be updated to the latest version of iOS or iPadOS.