iTunes not updating iPhone SE and iPad

My iPhone SE (2nd Generation) is currently updated to iOS 18.7.2,However, the software update shows that I should update to iOS 26.1. I tried to update my iPhone using i Tunes (version 12.13.9.1) but it says that the iPhone is updated with the latest version 18.7.2. I have had the same problem on my iPAD where iTunes says I have the latest update at 17.7 .2 and does not recognise iPadOS 18.7.2. With only 32GB of storage even stripping back my applications there is no room to update my system without using iTunes. Can someone help this old codger?