My iPad is not updating

Whether or not you are able to update your iPad to a newer version of iOS/iPadOS will be dictated by your iPad model - and the currently installed version of iOS. You can find this information here:

Settings > General > About

Not sure which iPad you have? Identify your iPad model.

Here is a list of the highest version of iOS supported by the older models of iPad (for simplicity - “generations” are shortened to a number) that are restricted in their ability to be updated:

iPad1 - iOS 5.1.1

iPad2, iPad3 and iPad mini1 - iOS 9.3.5 (WiFi Only models), iOS 9.3.6 (WiFi & Cellular)

iPad4 - iOS 10.3.3 (WiFi Only), iOS 10.3.4 (WiFi & Cellular)

iPad Air1, iPad mini2 and iPad mini3 - iOS 12.5.4

Newer models, not appearing in this list, are all able to be updated to the current version, iPadOS 14.6

The tags appended to your post suggest that you have a first generation iPad Air.

The iPad Air1 can only be updated to iOS 12.5.4. Apple ended major update support for the Air1 in September 2019 - although this and similar models continue to receive “point” security updates, the most recent being just a few days ago. The Air1 cannot be updated to iPadOS 13 (or any later major versions of iPadOS) as the internal hardware does not meet the minimum technical requirements (CPU and RAM) for more recent versions of iOS/iPadOS.

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

An iPad Air 1st generation cannot support iOS versions beyond 12.5.4, because of hardware (CPU/RAM) incompatibility, sorry.

Regards

Giulio