I just did the current update and now my Ipad is stuck in a loop of Apple Screen and Enter Passcode

Your next step is to restore you iPad to factory settings.

As your iPad is unstable, you’ll need to use either a PC (with the most recent version of iTunes installed) or a Mac (with iTunes, or Finder, as appropriate for the installed version of MacOS).

https://support.apple.com/en-gb/HT201252

A first step would be to force-restart your iPad - as this often resolves isolated issues:

• On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
• On an iPad with Face ID: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.

If this doesn’t resolve the problem, we can look deeper.