iPad iOS version

the first generation ipad mini from 2012 can't be updated higher than iOS 9.3.6

the second generation ipad mini from 2013 can't be updated higher than iOS 12.4.3

https://en.wikipedia.org/wiki/IPad_Mini

Apple formally ended Update Support for the original iPad mini is September 2016. The final supported/available iOS version for your iPad is iOS 9.3.5 (WiFi Only models) or iOS 9.3.6 (WiFi & Cellular models).

As the internal hardware of the iPad mini does not meet the minimum system requirements for newer major versions of iOS/iPadOS, your iPad mini cannot be updated.

You may wish to consider that compatible Apps for your iPad are increasingly difficult to find - as third-party developers are increasingly dropping support for older versions of iOS preceding iOS12. As older versions of Apps are removed from the Apple App Store, you’ll not be able to (re)download or install them. As such, if you want or need to access most current Apps, you’ll need to consider replacement of your iPad with a newer or current model.

Even the most basic current iPad 10.2 will massively outperform you current iPad - and is compatible with the vast majority of current Apps.

I hope this information is helpful in outlining your current options.

Minor correction: iPad mini2 (a.k.a. IPad mini Retina) is iOS 12.4.6.