how do I know if my iPad can upgrade from 12.5.4 to 13.1.2?

Hi there,

If you don't know which iPad you have, you can identify your iPad model here:

https://support.apple.com/en-ca/HT201471

Once you have that information, check to see if your iPad is in the list at the link below. If it does not appear in the list, you cannot upgrade from iOS 12.5.4.

https://support.apple.com/en-ca/guide/ipad/ipad213a25b2/13.0/ipados/13.0

Note that iPad models supporting iOS 13 (now called iPadOS 13) should also support iPadOS 14, meaning if you can, you would have to update to version 14 instead of 13.

Cheers!

Edit: As mentioned by @Niel, because you were able to update to iOS 12.5.4, your iPad shouldn't support any iOS version above iOS 12.

You can't. 12.5.4 was only released for models incapable of 13 or above.

(200424)