Ios 12 on mini ipad 2

https://www.apple.com/ios/ios-12/

Update your iPhone, iPad, or iPod touch - Apple Support

if this does not work then likely you dont have an iPad mini 2 but own and iPad mini 1

wiki says yes https://en.wikipedia.org/wiki/IPad_Mini_2

That is a 1st gen iPad Mini.

That iPad cannot upgrade beyond iOS 9.3.5.

Its hardware is too old and too underpowered.

Tap my link below for my full explanation.

About iOS 10/11/12-iPad Mini 1st Generati… - Apple Community

The iPad 4th generation is, also, ineligible and excluded from upgrading to iOS 11 or iOS 12 and any future iOS versions.

With the introduction of iOS 11, ALL support for older 32-bit iDevice hardware and any iOS 32 bit apps has ended.

Your iPad 4 is an older, 32-bit hardware device.

With the introduction of the 64 bit coded iOS 11, and now iOS 12 and later, ALL newer iOS versions will ONLY support newer 64 bit hardware iDevices and 64 bit software, now.

The iPad 4 is incompatible with all of these new iOS versions, now.

No need to panic or worry though.

Your iPad 4th gen will still work and function as it always has, but will no longer receive any more app updates sometime in the foreseeable future.

The 4th gen iPad has had over 5 years of iOS upgrades/updates

The final app updates your 4th gen iPad will receive will be its last!

Your iPad 4 will survive and stay a viable, functioning iPad for a couple more years.

Currently, iPad 4 models are STILL receiving regular app updates, but look for this change over time.

This is why Apple introduced the new, lower cost 2018 and 2017 iPad 6th and 5th generation models.

Apple is trying to get older iPad 2, 3, 4 and 1st gen Mini iPad users to upgrade to more modern iPad hardware in anticipation of the recent releases of iOS 11, and now iOS 12, which will render all older 32 bit iDevices obsolete, in time.

Also, since the iPad 4 has not had any new iOS upgrades/updates in over a year, I would strongly consider you stop using that year old, default iOS Safari Web browser and seek out other more current and, up to date and more secure third party Web browsers, instead.

Here are a few, more popular, third party web browsers that I know are STILL being updated and supported on iOS 10 and earlier.

Firefox Web browser

Google Chrome browser

iCab Mobile Web browser

Dolphin Web browser

Dolphin Incognito Web browser

DuckDuckGo private Web browxer

Snow Bunny Web browser

Private Browsing Web browser

Aloha Web browser

Maxthon Web browser

Good Luck to You!