How can i update my iphone when there's nothing says update your phone

Please tell us which iPhone you have by checking the following:

Open Settings ➔ General ➔ About ➔ Model Name : Tell us exactly what you see here.

Then tell us which iOS version that you currently have and which iOS version as you trying to update to. You can attempt to manually update your iPhone over a Wi-Fi Network by opening:

Settings ➔ General ➔ Software Update : If there is an update available then you will be asked to update your iPhone.

If you have an iPhone 6 (Not the iPhone 6s ) then you will only be able to update up to iOS version 12.4.9. No further updates are available for the iPhone 6 and older iPhones.

Axel F.