Nope.
This will never be possible.
A 4th gen iPad cannot be upgraded beyond iOS 10.3.3/10.3.4.
A 4th gen iPad is a nearly 7-1/2-year old device, now!
Its internal hardware is too old, underpowered and completely incompatible with any of the current and future versions of iOS/iPadOS.
Sorry. It is what it is at this very late date.
If you need an iPad that can run the latest and greatest versions of iOS, as well as, the most current apps available, then, you will need to purchase a new iPad from Apple or a discounted, refurbished iPad from Apple’s Refurbished & Clearance section of Apple’s Website.
These old iPad 2, 3, 4 and 1st gen iPad Mini models are nearing 8 and 9-years old, now.
As of the beginning of 2019, many, MANY third party app developers are all more quickly and completely dropping older app support for all old 7, 8 and 9-year iPads that are running 2-3 year old and earlier iOS versions.
Third party app developers are removing all of their older, legacy versions of their apps from Apple's App Store servers, now.
Older versions of apps are going to be gone for good, now!
Getting older versions of app for these old iPad models, initially from Apple’s iOS App Store is getting to be very difficult and problematic, now, and will only be getting much worse in 2020.
These old iPads are now reaching their complete end of life and support.
Old iPads that can no longer be upgraded/updated will have NO MORE APPS AVAILABLE for initial download, at all, soon, from the Apple iOS App Store, for such old iOS devices in the very near future.
Older versions of apps for older iPads will be completely gone, very soon!
This is now the time to seriously consider a new or discounted, refurbished iPad from Apple or other Apple authorised resellers.
Amazon currently has, new sealed in box, Apple's base model 2019, 7th gen, 10.2 inch screen, WiFi ONLY 32 and 128 GBs iPad models selling for $249 and $329, respectively.
https://www.amazon.com/gp/product/B07XQYPM2N?pf_rd_p=ab873d20-a0ca-439b-ac45-cd78f07a84d8&pf_rd_r=6HW54HFD0YSC2ZE3CP7Z
These 2019, 7th gen iPads have much faster processors, at least 3 times the internal RAM, iPadOS 13 support, Apple Pencil and Apple Smart keyboard cover support and have better audio speakers and built-in cameras.
A lot has happened with iPad and iOS in 7-9 years and in the past 2 to 3-1/2 years since iOS 9 and 10.
Sorry & Best of Luck to You!