my ipad air4 unlocking issues

Start here >>> If Touch ID isn't working on your iPhone or iPad - Apple Support

Some users just have difficulty using TouchID. The causes for of TouchID being unreliable for some users - and not others - are many. Whilst not an exhaustive list, possibilities include:

• Very high humidity (“sweaty” fingers)
• Very low humidity (excessively dry skin)
• Poor fingerprint ridge-detail (excessive hand washing - or exposure to abrasive material, damaging fingerprint detail)
• Physical injury (cuts or splits to the fingertip)

If you have naturally dry skin, try using a “light” (non greasy) and easily absorbed skin moisturiser.

Due to the much smaller scanning surface, TouchID sensors that built-in to the top button of some models of iPad Air are perhaps more susceptible to issues than the earlier (larger) sensors built-in the the Home Button.

If you continue to experience difficulties, you might be best advised to seek assistance directly from from Apple Support. You can contact the Support Team using the Get Support link at top-right of this page. Alternatively, you can initiate and manage your support cases 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

You might also visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to test and assess your iPad:

Genius Bar Reservation and Apple Support Options - Apple