I want to update my phone to be able to download some app
To be able to download some app
iPhone 6, iOS 12
Marking your own post as Solved may prevent others from trying to help because they think you have fixed your problem.
An iPhone 6 can't be updated past IOS 12.5.5.
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. *