If your iPad model has been stuck on iOS 10 for all of these past years, then it is possible you own an almost 9-year old, 2012 iPad 4th generation.
That iPad model cannot ever upgrade beyond iOS 10.3.3/10.3.4.
Your 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!
AND, that nearly 5-year old default iOS Safari Web browser is too old, not secure and not safe to use to access the Internet, any longer.
There are virtually NO MORE third party Web browsers left for 8-10 year old iPads!
Available and more popular third party Web browser choices are GONE, now!
If you must use these old iPad models, here is what is left for still updated Web browsers.
Pickins’ are slim, now!
ALook Web browser ( A fairly new Web browser primarily designed for old iOS device versions, but is still available to newer iOS/iPadOS devices, as well ). I recommend this “new-ish” Web browser for old iPad models.
Dolphin Web browser
Maxthon Web browser
TOR private browser
TOR + VPN private browser
Turbo VPN private browser
This is pretty much it for iOS 9/10 compatible device, up to date, third party Web browsers today, in 2021.
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 OR ONLY able to purchase older, less expensive iPad models, look at older IPads from 2014 and later.
All of these older model iPads, below, 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.
Also, A 128 GBs storage iPad starts out with approx. 120 GBs.,after initial internal flash drive formatting.
Minus approx. 4-6 GBs for iOS/iPadOS leaves between 114-116 GBs.
Minus 3- 6GBs, for iOS/iPadOS system operational reserve, that MUST BE MAINTAINED AT ALL TIMES, to ensure/insure normal, expected operation of iOS/iPad OS, leaves approx. between 108-110 GBs of actual, usable data storage space.
Your internal data storage is getting dangerously close to the operational minimums.
So, you need to manage that 120 GBs of internal data storage on that iPad much better.
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!