For reasons known only to Apple, the battery health feature has until recently been an exclusive feature of iOS for iPhone. Prior to release of recent models of iPad Pro, iPad Air and iPad mini, iPad has never had the Battery Health feature - most likely because iPad batteries are both considerably larger and have a much longer service life than iPhone.
An iPad battery is rated to maintain at least 80% of its initial capacity after 1000 full charge/discharge cycles.
For older models of iPad that don't have the battery health feature, 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/
The are also third-party shortcut scripts available that can semi-automate analysis of your iPad's analytics files - and provide a calculated estimate based upon the charge-cycle count. If this method is of interest, try using a Google search for "iPad battery health shortcut".
Warning: Be aware that running third-party shortcuts, downloaded from external sources, carry risk - in that they may not work, may be malicious, or may export private/sensitive data from your device. Use shortcuts entirely at your own risk; if anything goes wrong, you're on your own.
If you are experiencing difficulties with your iPad battery holding charge, you might be best 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.
Genius Bar Reservation and Apple Support Options - Apple
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