You don't.
If your iPad has been stuck on iOS 10.3.3 for the past few years, with no major upgrades/updates forthcoming, then you own a 2012, iPad 4th generation.
A 4th gen iPad cannot be upgraded beyond iOS 10.3.3/10.3.4 for WiFi & cellular data models.
A 4th gen iPad is a NEARLY 8-year old device, now!
These older iPad models are too old, now, too underpowered and completely incompatible with any of the current and future versions of iOS/iPadOS.
Sorry, but it is what it is, today, in the year 2020!
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 need to purchase a new iPad from Apple or a discounted, refurbished iPad from Apple’s Refurbished & Clearance section of Apple’s Website or a new or refurbished iPad from an Apple authorised, third party retail or online reseller OR other trusted sources for new or used Apple products.
These old 8 and 9-year old iPad models are going to be OBSOLETE by the end of 2020!
Here's why and what you will need to do about it in 2020!
Tap and thoroughly read my links below for my additional info about your old iPad model.
If you own OLD 8 and 9 Year Old iPad mo… - Apple Community
"Sudden App Death” for Completely Res… - Apple Community
Time to consider a new, new refurbished OR much, MUCH “newer”, used iPad model.
Sorry & Best of Luck to You!
