The 2013 iPad Air 1 ( “A” model number A1474/1475/1476 ), iPad Mini 2 ( “ A” model number A1489/1490/1491 ) and the 2014 iPad Mini 3 ( “A” model number A1599/1600/1601 ) cannot upgrade beyond any version of iOS 12.
These iPad models have overall internal hardware that is too old, too underpowered and incapable of running all of the new, advanced and internal hardware resource intensive features of the newest iPadOS versions.
These iPad models are all over 8 and 9-years old, now, in 2022.
Sorry.
Third party app support, typically, continues for 2-3 years AFTER Apple ends full support of a subset of their devices.
The last major update to iOS 12 was in 2019, with iOS 12.3.
Apple has stopped issuing any major iOS 12 updates for these very old iPad models and have been ONLY issuing security, “point” updates for the past few years.
So, year three is coming to an end and third party app support has been on a steady, downward/decline trend for all iOS 12 supported devices.
Many popular third party apps are no longer available to 9 to 10-year old iPad models that are, permanently, stuck at some version of iOS 12.
Look for many more third party apps dropping support for all iOS 12 supported devices as the 2022 year progresses to its end and into the beginning of 2023.
The immediately above statement is what you really need to worry about.
In addition, the various iOS 12 Web browsers, that were once available for these older iPad models, should still be safe to use for a while longer, you can still use that iPad the way it has always been used, but know that 8 to 9-year old iPad models will no longer have access to any current apps.
Plus, no way to know when Apple will cut off all security support for these 8 and 9-year old devices.
Also, the internal, rechargeable batteries in these old iPads are, also, running on borrowed time.
Not worth the costs to replace these old internal, rechargeable batteries in these old iPads, any longer, either.
Also, these very old iPad models have NO real trade-in nor any resale value, either.
Sorry.
You need to consider that it is the Fall of 2022, now.
iPadOS 16.1 is here!
These 8 to 9-year old, iOS 12 iPad models are coming to the full end of their support life.
These iPad models will be 4 OS iterations behind, now.
You really need to seriously consider a purchase of a new iPad model OR a much, MUCH “newer” and less expensive, refurbished or used iPad models, from better known, trusted sources, like other Apple product/device retailers/resellers, some locally or from online, on the Web/Internet, capable of running the latest iPadOS versions.
There are PLENTY of newer, older iPad models that can run the latest, current versions of iPadOS.
If you need OR ONLY able to afford to purchase older, less expensive iPad models, look at older IPads from 2015 and later.
All of these older model iPads below CAN, currently, run the latest releases of iPadOS 16.
2015-2017, 12.9 inch screen iPad Pro models ( 1st gen Pencil support )
2016 9.7 inch screen iPad Pro models ( 1st gen Pencil support )
2017, 10.5 inch screen iPad Pro models ( 1st gen Pencil support )
2017, 9.7 inch screen iPad 5th gen models ( NO Pencil support )
2018, 9.7 inch screen iPad 6th gen models ( 1st gen Pencil support )
2019, 10.2 inch screen iPad 7th gen models ( 1st gen Pencil support )
2020, 10.2 inch screen iPad 8th gen models ( 1st gen Pencil support )
2018, 11 inch or 12.9 inch screen iPad Pro models ( 2nd gen Pencil support )
2019, 10.5 inch screen iPad Air 3rd gen models ( 1st gen Pencil support )
2019, 7.9 inch screen iPad Mini 5th gen models ( 1st gen Pencil support )
Get the largest internal data storage model you can afford as NO Apple iOS device has ANY expandable storage.
I am sorry that you had to learn all of this, but this does not change any of the facts regarding these older iOS devices.
Sorry & Best of Luck to You!