How to upgrade the iPhone
I need to upgrade my iPhone 6plus
iPhone 12 Pro
Marking your own post as Solved may prevent others from trying to help because they think you have fixed your problem.
IOS upgrade? An iPhone 6 Plus can't be upgraded past IOS 12.
See the article(s) below.
IOS 15 and iPadOS 15 Compatible Devices. *
iOS 14 and iPadOS 14 Compatible Devices. *
iOS 13 and iPadOS are compatible with these devices - Apple Support. *