iPhone 6, want to update from 12.5,to14.5! So I can add google chrom, which I need for square

Hello. Your iPhone 12 is too old to run a recent version of iOS and can only upgrade to iOS 12.5.5 at the latest. If you want to run a newer version of iOS, such as iOS 15, you will need to upgrade to a new iPhone.

No. You cannot run iOS 13.5 either. The maximum version of iOS your iPhone 6 will run is iOS 12. This will not change as this device is very old and has limited CPU and memory resources.

If you would like to run a newer version of iOS, such as iOS 15, you will need to upgrade to a newer device. A list of iPhones compatible with iOS 15 is below.

These iPhone models are compatible with iOS 15.

No, the iPhone 6 does not have sufficient RAM to run iOS 13 or later and you cannot add RAM to your iPhone. You will have to get a newer iPhone.

What about iOS 13.5 on iOS 12.5