I want to update my iPhone 6s plus

Make sure that your iPhone is setup to meet the following requirements before you attempt to update the iOS version over a Wi-Fi Network. Open Settings ➡️ General ➡️ Software Update: If there is an update available for your iPhone then it will be listed here. Follow the on-screen instructions to download and update your iPhone. 

• 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).

If you can't see the update on your device, use your computer to update your device manually. Learn how to update your device manually if you're using a Mac with macOS Catalina or later, or if you're using a Mac with macOS Mojave or earlier or a Windows PC.

Axel F.

• iOS 15 and iPadOS 15 are compatible with these devices - Apple Support

//support.apple.com/en-us/HT212712 [includes your iPhone 6s Plus model]

• How to update to iOS 15 or iPadOS 15 - Official Apple Support

//support.apple.com/ios/update

• Update iOS on iPhone - Apple Support [steps to backup/update iPhone]

//support.apple.com/guide/iphone/update-ios-iph3e504502/15.0/ios/15.0

• Connect iPhone and your computer with a cable - Apple Support

[includes update by wire to Mac/PC. See Update iPhone ]

• iPhone User Guide (Table of Contents) 15.1 - Apple Support

//support.apple.com/guide/iphone/toc/15.0