I’m unable to upgrade software, nor am I getting notification to upgrade software. Why is this so?

IOS_upgrade wrote:

Thanks for replying!

I have iPhone 6 Plus

Its running on iOS 12.5.5

Settings->General->Software Update?

Your phone is using the latest version of iOS that it supports. It cannot be upgraded beyond iOS 12.5.5.

What iPhone model do you have?

What iOS version is it currently running?

What happens when you go to Settings->General->Software Update?

12.5.5 is the last iOS version the iPhone 6 Plus can run. It lacks the hardware for anything newer. It's 8 year old hardware at this point.