How can I upgrade my Ipad 5

Perhaps your iPad is not a 5th generation model (most likely a 4th gen model, which cannot be updated beyond 10.3.x, because of hardware incompatibility).

See this:--> Identify your iPad model - Apple Support

If it is a 5th generation, it can be updated to iPadOS 14 or later.

Regards

Giulio

You don’t.

If your iPad model has been stuck on iOS 10 for all of these past years, then you own an over 8-year old, 2012 iPad 4th generation.

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

Your over 8-year old, iPad 4th gen model is too old, now.

Apple ended support for 8-10 year old iPads, at least, over 3 years, ago.

The internal hardware in that iPad is too old, too underpowred and completely incompatible with all later versions of iOS/iPadOS.

Virtually, all third party iOS app developers ended/stopped/abandoned supporting these old iPads over two years, ago.

There are virtually, NO MORE older iOS 9 or 10 compatible apps available from the Apple iOS App Store, any longer.

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

Sorry.

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 new iPad model OR a much “newer” , used iPad model capable of running the latest iPadOS versions.

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

Sorry & Best of Luck to You!

If you do, in fact, have/own a 2017, iPad 5th generation that is still running iOS 10, then your iPad is too far behind in iOS/iPadOS upgrades/updates .You would need to use a Windows PC or older Mac, connected to the Internet, using the latest version of iTunes and let iTunes upgrade your 5th gen iPad to the latest iPadOS 14.3.

If you own a newer Mac with a much newer macOS, then you use the macOS Finder to upgrade that 2017, 5th gen iPad to iPadOS 14.3.

Best of Luck to You!