Your iPad is approaching full!
That is why your iPad will not install the latest iPadOS 14.4.
A 32 GBs storage iPad starts out with approx 30 GBs.,after initial internal flash drive formatting.
Minus approx. 5-6 GBs for whatever iOS/iPadOS your lPad is currently runnng, leaves 24-25 GBs.
Minus 2-4 GBs, for iOS/iPadOS system operational reserve, that needs to be maintained at all times, leaves approx. between 20-23 GBs of actual, usable data storage space.
Your iPad is at is operational minimum of internal, free data storage space now.
You need to free up, at least and additonal 5-6 GBs of additional, free internal data storage space to install the current iPadOS 14.4.
You need to free up free data storage space on an iPad/iDevice,.
You need to start by backing up your iPad to either Apple's iCloud ( you may need to pay for additional, monthly storage space ) or by connecting your iDevice to a computer running the latest iTunes or, if a newer Mac with a much newer macOS, use the macOS Finder to do the device backup and/or some other offsite, “cloud” data storage/backup services, like Google Drive/Photos, BOX, DropBox, Amazon Cloud Drive, Flickr ( for photos/images ), etc.
Then, delete any installed apps that you no longer use or use infrequently enough that they aren't missed (you can always reinstalled any purchased or free apps at some time later, as you need them).
In addition, uninstall any games that appear to be using a sizable chunk of your iPad's internal storage, as needed.
Then, thin out/delete any music/videos/movies/TV shows/podcasts/screen recordings/images/eBooks/
eMagazine/iBooks/audio books/Documents/PDFs, etc.
If you use a POP email account on your iPad, delete/thin out any old saved emails that maybe saved to your iPad.
To permanently delete photos/images off of your iDevice go into the Photos app and find the Recently Deleted folder/album and permanently delete any photos/images stored in that folder/album.
Also, you can check to see what other stuff is eating up all your valuable data storage space by going into the Settings App,,General Settings Panel, in the right hand column, tap Storage & iCloud usage panel ( in iOS 11 and later, it’s now called iPad Storage ), in the top Storage Panel, tap the Manage Storage panel, wait for a list of apps to generate that will tell you how much space each app is taking up on your iDevice.
Then, for older iPads or iPads with a Lightning connector, do a hard reset of your iPad by holding down both the Home and sleep/wake buttons simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons.
iOS devices and iOS/iPadOS need to maintain, at the very least, a minimum of between 2-4 GBs of free data storage space, AT ALL TIMES, to insure normal/nominal functionalities/operation and general overall performance of any iOS device running iOS/iPadOS.
After all of this has been accomplished, you should be able to download/install the current iPadOS 14.4 upgrade/update.
Best of Luck to You!
