Is there a way to see the battery capacity on a iPad Pro (11-inch) 2nd generation?

The battery health feature is exclusive to iOS for iPhone. iOS/iPadOS for iPad has never had the Battery Health feature - most likely because iPad batteries are both considerably larger and have a much longer service life. 

An iPad battery is rated to maintain at least 80% of its initial capacity after 1000 full charge/discharge cycles - whereas an iPhone is rated to have 80% of initial capacity after 500 full cycles.

There are software packages available that can access battery cycle count. Popular choices for Mac are Coconut Battery and iMazing - whereas iMazing is available for PC:

https://www.coconut-flavour.com/coconutbattery/

A further option is to use the iPadOS Shortcuts App - and install the relatively well known "Battery Stats" shortcut. For the installed Shortcut to be useable, you will also need to enable Analytics for your iPad:

Settings > Privacy & Security > Analytics & Improvements > Share iPad Analytics - set to ON

If you experience difficulties with your iPad battery holding charge, you might be well advised to have your iPad tested.  If you directly contact Apple Support - and explain your problem - you can request a remote battery diagnostic. The tests will confirm the status of your battery - and other elements of your iPad’s health.

Alternatively, a visit to the Genius Bar at your local Apple Store would provide opportunity for your iPad to be similarly tested by the Apple technicians - after which you can explore your available options.

You can contact Apple Support using the Contact Support link at top-right of this page. You can also initiate a support case using the excellent Apple Support App; if not already installed on your iPad, the App can be downloaded from the App Store:

https://apps.apple.com/gb/app/apple-support/id1130498044

There are third-party apps that purport to give you that information. Coconut Battery is one I've seen recommended.

But, honestly, it's information that you can easily do without. The only times you need to know the capacity is 1) just before your warranty ends so you can determine if you need a new battery before it ends. And you probably won't or 2) if you're having ongoing problems. In that case, contact Apple and have them run diagnostics. They can be done remotely and are more accurate than anything you could find by yourself.

Genius Bar Reservation and Apple Support Options - Apple