Why the app not working in this ipad

Please be more specific as to "not working."

Several things to try:

Have you restarted your device? That sometimes clears up odd issues.

If an app on your iPhone or iPad stops responding, closes unexpectedly, or won’t open, click here --> https://support.apple.com/HT201398

Redownload apps, music, movies, TV shows, and books from the iTunes Store, iBooks Store, and App Store - https://support.apple.com/HT201272

How to contact an app developer - https://support.apple.com/HT207959 - for problems running an app or problems restoring purchases

If you still have problems click here --> https://support.apple.com/choose-country-region/Select your country, then a product.

URL correction:

If you still have problems click here --> https://support.apple.com/choose-country-region/ Select your country, then a product.