How to update my iOS to view an unsupported note?

To update the iOS on your iPhone, follow these steps:

1. Connect your iPhone to a Wi-Fi network.
2. Go to the "Settings" app.
3. Tap on "General."
4. Tap on "Software Update."
5. If an update is available, you will see a message saying "iOS X.X.X is available. Tap Install Now to install the update."
6. Tap "Install Now."
7. If prompted, enter your passcode to continue.
8. The update will begin downloading. When it is finished, tap "Install" to install the update.
9. Your iPhone will restart and the update will be installed.

It is a good idea to make sure that your iPhone is charged to at least 50% before attempting to update the iOS. You may also want to back up your iPhone to iCloud or iTunes before updating in case anything goes wrong during the process.