I want to update my iPhone 6s to iOS 15.72.2

Hey ayomide30,

You can find the steps to update your iPhone in this article: Update your iPhone or iPad

"Update your iPhone or iPad wirelessly

1. Back up your device using iCloud or your computer.
2. Plug your device into power and connect to the internet with Wi-Fi.
3. Go to Settings > General, then tap Software Update.
4. If you see more than one software update option available, choose the one that you want to install.
5. 
6. 
   
7. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.

If you get an alert when updating wirelessly

Learn what to do if you see an alert message while trying to update your device wirelessly."

Thanks!