I have found a program where I can see the battery health from my iPad and also from all others Apple Devices. It names "iMazing" and I think very similar to the Coconut Battery which is mentioned in another answer.
After downloading and installing, I must connect my iPad with a USB-lightning cable to my MacBook Pro where I have downloaded iMazing.
Then open iMazing, and the program will detect your connected iPad, and you must press trust on your iPad, that iMazing can access to the iPad's information. Then you will see a screen like below:
On the bottom right (red arrow), click to the battery-logo, and you will become all relevant information to your connected device (in my example from my iPad Pro). But as you can see, you can do a lot other things with this program: