Update difficulties
My iPad mini has iOS 9.3.5 but claims it is up to date so won't download any more updates. What to do?
iPad Mini Wi-Fi, iOS 9.3.5
You have a 1st generation iPad Mini.
A 1st generation iPad Mini cannot be upgraded/updated past iOS 9.3.5.
That iPad model is 5 years old, now.
The hardware is too old and too underpowered to run/support newer versions of iOS.
Sorry.