I can’t update my iPad Air 2 w automatic updates

The tags appended to your post suggest that you have an iPad Air2. If you do have an iPad2, then your iPad can be updated to iPadOS 14.4 - this being the current version at time of writing.

However, if you actually have a first generation iPad Air, you will not be able to update beyond iOS 12.5.1. Some owners have been known to misidentify an iPad Air1 as an iPad Air2; if iOS 12.5.x is installed, then you most certainly have an iPad Air1.

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

If your iPad is capable of being updated to a more recent version of iOS/iPadOS than is currently installed, these support pages outline both the available methods by which the update can be performed - and troubleshooting should you experience difficulties:

Update your iPhone, iPad or iPod touch – Apple Support

If you can't update or restore your iPhone, iPad or iPod touch – Apple Support

If your iPhone, iPad or iPod touch won’t update - Apple Support

iOS update and restore errors – Apple Support

There are no software updates for your device.