I want to update my phone iOS

This is an apple user to user forums

If you want to update your iOS , the iPhone 6s can update until iOS 15.8

The iPhone 6 cannot update further then iOS 12.5.7

If you have indeed an iPhone 6S go to settings>general>software update and make sure to turn off low power mode and to connect to a wifi network.

If updating wirelessly is not working, please update via a pc or Mac instead

Update your iPhone using a Mac with macOS Catalina or higher

On a Mac with macOS Catalina or higher, you will use the finder in order to upgrade your iPhone. Make sure to Back up your device before starting the upgrade process.

On a Mac with macOS Catalina or later, you will follow the following steps:

1. Open a finder window
2. Connect your device to your Mac via a lighting to usb A or a lightning to usb c cable On the iPhone 15 series, use an usb c to usb c cable.
3. Select your device in the left sidebar of the finder window
4. click general, then click check for update
5. Click download and update.
6. If asked, enter your iPhone passcode

Update your iPhone via a Mac running macOS Mojave or earlier, or on a Windows PC

On macOS Mojave or earlier, or on a windows machine, we won't use the Finder to upgrade your iOS

Instead, we will use iTunes. Make sure to Back up your device before doing any update or upgrade to your phone.

1. Open iTunes
2. connect your device to the computer with an lightning to usb a or a lightning to usb c cable. On the iPhone 15 series, use an usb c to usb c cable.
3. Click device button in the iTunes toolbar
4. In the summary tab, click check for update
5. Click download and update, follow The on screen instructions
6. If asked, enter your iPhone passcode.

Updating/upgrading your iPhone - Apple Community

If this is an iPhone 6s Plus, see: Update your iPhone or iPad - Apple Support

Note that the 's' in the model name is significant. The iPhone 6 Plus (no 's') is an earlier model that cannot run any version of iOS later than the most recent update to iOS 12.

This is not a real-time chat line, and most of the people you are talking to are not Apple employees.

It is not realistic to post something like "I want to update my phone OS" – and then wait only ONE MINJTE before posting "You didn't reply me back now."