I can't update to iOS 14

Older iPads cannot be updated to the current iPadOS. The iPad 4th generation, for example, cannot be updated beyond iOS 10.3.3.

Also see the following from iPadOS 14 - Apple

iPadOS is compatible with these devices

• iPad Pro 12.9-inch (5th generation)
• iPad Pro 11-inch (3rd generation)
• iPad Pro 12.9-inch (4th generation)
• iPad Pro 11-inch (2nd generation)
• iPad Pro 12.9-inch (3rd generation)
• iPad Pro 11-inch (1st generation)
• iPad Pro 12.9-inch (2nd generation)
• iPad Pro 12.9-inch (1st generation)
• iPad Pro 10.5-inch
• iPad Pro 9.7-inch
• iPad (8th generation)
• iPad (7th generation)
• iPad (6th generation)
• iPad (5th generation)
• iPad mini (5th generation)
• iPad mini 4
• iPad Air (4th generation)
• iPad Air (3rd generation)
• iPad Air 2

That iPad is too old.

Upgrading/updating that iPad any farther will never, ever be possible.

If your iPad model is stuck on iOS 10, then it is possible you have an almost 9-year old, 2012 iPad 4th generation.

That iPad model cannot ever upgrade beyond iOS 10.3.3/10.3.4.

That nearly 9-year old, iPad 4th gen model is too old, now.

Sorry.

Apple ended support for all 8-10-year old iOS devices nearly 5 years, ago, in 2016.

Third party app developers abandoned and stopped supporting these 8-10-year old iOS devices nearly 3 years, ago, in 2018.

There are, virtually, NO MORE third party apps available from the iOS App Store, any longer!

Third party compatible apps for such old devices are few and far between, now, in 2021.

This includes apps for both iOS 9 AND iOS 10 devices!

Simply put, a 4th gen iPad is too old and obsolete now.

Sorry, but this is the reality for ALL 8-10-year old AND OLDER iOS devices now. Especially now in 2021!

If you need/want an iPad with an up to date iPadOS with access to current, updated apps, then you really need to seriously consider a purchase of a new iPad model OR a much, MUCH “newer” and less expensive, refurbished or used iPad models, from better known, trusted Apple product/device retailers/resellers, some locally or from online, on the Web/Internet, capable of running the latest iPadOS versions.

There are PLENTY of less expensive, newer, older iPad models that can run the latest, current versions of iPadOS.

If you need to purchase older, less expensive iPad models, look at older IPads from 2014 and later.

All of these older model iPads CAN run the latest iPadOS versions and the up and coming iPadOS 15.

2014, 9,7 inch screen iPad Air 2 models

2015, 7.9 inch screen iPad Mini 4 models

2015-2017, 12.9 inch screen iPad Pro models. ( 1st gen Pencil support )

2016 9.7 inch screen iPad Pro models ( 1st gen Pencil support )

2017, 9.7 inch screen iPad 5th gen models

2018, 9.7 inch screen iPad 6th gen models (1st gen Pencil support )

2019, 10.2 inch screen iPad 7th gen models ( 1st gen Pencil support )

2020, 10.2 inch screen iPad 8th gen models. ( 1st gen Pencil support )

Get the largest internal data storage model you can afford as NO Apple iOS device has expandable storage.

I am sorry that you had to learn all of this, but this does not change any of the facts regarding these very old iOS devices.

Sorry & Best of Luck to You!