The battery health feature is exclusive to iOS for iPhone, inclusion of this feature being relatively recent.
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 third-party software packages available that can access battery cycle count. Popular choices for Mac computers are Coconut Battery and iMazing - whereas iMazing is available for Windows PC.
https://www.coconut-flavour.com/coconutbattery/
If you are experiencing difficulties with your iPad battery holding charge, you might be best advised to first 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 Support link at top-right or bottom-left 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/app/apple-support/id1130498044
