If a message says that an update is available, tap Install Now to update now. Or you can tap Later and choose Install Tonight or Remind Me Later. If you tap Install Tonight, just plug your device into a power source at night, and your device will update automatically overnight.
You can also follow these steps:
- Plug your device into a power source and connect to the internet with Wi-Fi.
- Go to Settings > General, then tap Software Update.
- If you see two software update options available, choose the one that you want to install.
- Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now.
Please note: It is important to ensure your device is up-to-date with the latest software updates via Apple. Remember, you will also need to update your apps via the AppStore to ensure they are compliant.