iPad mini2 can to update version ?

Sorry, update of your to iPadOS14 is not possible.

An iPad Air1, mini2 or mini3 can only be updated to iOS 12.5.1.

Apple ended major update support for these models of iPad in September 2019. Whilst these models have since continued to receive “point” security updates, they cannot be updated to iPadOS 13 (or any later major versions of iPadOS) as the internal hardware does not meet the minimum technical requirements (RAM and CPU) for newer versions of iOS/iPadOS.

Some App developers have dropped support for iOS versions preceding iOS 13.x for technical reasons (often because APIs or software libraries upon which they rely have been updated in the new version of iPadOS, making their App incompatible with earlier versions). 

Whilst many App titles remain compatible with your iPad, if you want or need to access to Apps requiring the most recent versions of iOS, you’ll need to consider replacement of your iPad with a newer or current model that supports iPadOS14.

Sorry, I appreciate that this may not be what you were hoping to learn.

I hope this information provides helpful clarity as to your available options - and the limitations of your existing iPad.

We can't help you, sorry, since your iPad Mini 2nd generation cannot support iOS versions beyond 12.5.1, because of hardware incompatibility.

Regards

Giulio