Why can I not up date my iPad to iOS 12 2

You own an iPad 4th generation which can only run iOS 10.

It can not run iOS 11, 12, 13 or any future iOS that apple releases.

There is no way to update the iPad, resetting to factory settings will make no difference.

Your device will not get higher than iOS 10. So you can not upgrade to iOS 12

Thanks

What is the “A” model number of your iPad?

The “A” model number of your iPad can be found on the lower area of the aluminium back of your iPad in small print letters right underneath the large, bold printed” iPad”.

What iOS version is your iPad currently running?

Go to Settings > General > About > Model

Tell us exactly which model you have and we can then tell you what your iPad can or can't be updated to.

Hey!

Do any error messages appear when you try to update the device?

Some information about your iPad model and currently installed version of iOS would be helpful:

Settings > General > About

Which iPad?