I have An Ipad air 4 tat ive charged it wont start screen stays black

Try a forced restart of your iPad Air 4th gen, using these instructions:

Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top (power) button. Only when the Apple logo appears (it might take 20-40 seconds), release that button

(ignore all other screens that might appear).

If the issue still persists, contact Apple support using this link:--> Get Support

Regards

Giulio

Try the new hard reset procedure for the 2018/2020 iPad Pro models without a Home button.

1. Press and release the volume UP button.

2. Then immediately press and release the volume DOWN button.

3. Then, press and hold the Power button at the top. You will see the Slide to Power off button, but keep on holding down the Power button until you see the Apple logo, then let it go.

Once you have performed all the steps, wait for a few seconds and your iPad Pro will boot up completely to the iPad Pro’s Lock screen.

Good Luck!