How do I update my iPad Air software to iOS 14

Here is how to update:

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

Given you’re asking about iPadOS 14 and have probably poked the software update button a few times, you’re several years back, and which usually means that your iPad is too old and unsupported by newer iPadOS versions; the hardware is not sufficient for newer iPadOS versions. No, there are no hardware upgrades. If your iPad is to old to update, your options are a newer (used, refurb) or new iPad.

Here are the versions supported by the current iPadOS, and this is the same list for iPadOS 13, iPadOS 14, and iPadOS 15:

If you decide to purchase used, here is the list for the next iPadOS version arriving later this year:

And some cautions about used-equipment purchases and some related and too-common scams:

… The All Too Common SAD Reality of Buying … - Apple Community

If you're referring to a first generation model, it's not capable of 13 or above. Otherwise, follow the instructions in the Related Article above.

It's no longer possible to update to exactly 14.

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