I am not able to update my IPhone 11 to iOS 15

Use internet speed over 15 Mbps (both download and upload) speed for error free update. Avoid latching on to Hotspot or WiFi Extenders

VPN or proxy connections might prevent your device from contacting the update servers.

• Get help with over-the-air iOS updates - Apple Support

• Remove and download the iOS update again

If you still can't install the latest version of iOS, try downloading the update again:

1. Go to Settings > General > [Device name] Storage.

1. Find the iOS update in the list of apps.

1. Tap the iOS update, then tap Delete Update.

1. Go to Settings > General > Software Update and download the latest iOS update.

If you don’t see the update in the list of apps or if the issue happens again, you need to update your device with iTunes.

Try updating iOS after each step.

• Try Forget the WiFi network and add again

• Try another WiFi network 

• Toggle sets automatically off and then on

• Reset your network settings

• Force restart your device

• Remove any beta profiles, if applicable

• If everything fails: - Use iTunes or Finder (for MacOS Catalina+) to update your device instead of over-the-air

• Get help with iOS update and restore errors - Apple Support

• If you see an error when you update or restore your iPhone, iPad

If your re attempting to update your iPhone over a Wi-Fi Network, then Make sure that your iPhone is setup to meet the following requirements before you attempt to update the iOS version-

• Your iPhone must have a fast Wi-Fi connection; you cannot update over cellular data or a cellular hotspot
• Ensure that you do not have a beta profile installed from a previous version
• The iPhone can not be in Low Power mode
• The battery state of charge must be above 50%
• Your iPhone must have at least 6GB or more free storage space
• Your iPhone cannot be connected through VPN
• You should leave the phone plugged in until it finishes updating, both to assure that it remains above 50% and to keep Wi-Fi enabled (Wi-Fi turns off when the phone sleeps if not connected to power).

Axel F.