How can I update to higher version of ios?

I don't know which iPad Model you have but your profile states that you have iOS version 10 installed on it.

If you have an iPad model 2015 or newer, then you can update all the way up to iPadOS 15.

Axel F.

If your iPad is on iOS 10 as your signature suggests, you have a very old iPad 4. It cannot run any of the newer versions past iOS 10.3.x. Since most apps no longer are compatible with such an out of date iOS version, it's time for a newer, more modern iPad at this point.