The version of iOS that you iPad is using can be found in Settings.
On the iPad home screen, look for the Settings icon:
Tap Settings to open the Settings app.
Scroll down to find General. And then tap About
Information about your iPad will be displayed.
Look for Version. This will tell you which version of iOS is running on your iPad
In this example, the iOS is 10.3.3.
You can also find the model number, and if you are running a recent version of iOS, the model name.
More information: http://osxdaily.com/2019/07/13/how-find-ipad-model-name/