How do I get the ‘Lockdown Browser’ to release my iPad?

First, try a hard reset, if you've not done that:

Step 1:

For iPads with Home Buttons: Hold down the home and on/off buttons at the same time.

For iPads without Home Buttons: Quickly press volume down, then quickly press volume up, then press and hold the on/off button. Skip to step 3.

Step 2: Continue holding the buttons even after the slider appears on the screen. The screen will eventually go black. 


The slider might not appear. Continue holding down the button until the screen goes black.



Step 3: When the Apple logo appears, let go of the buttons and let the iPad start up like normal.

If that doesn't help, you'll probably need to contact your school's IT department and talk to them about getting your iPad released.

Hope this helps. Regards.

Some suggestions:

To exit Lockdown Browser on your iPad, you can:

1. Turn off the iPad and boot into Recovery Mode by pressing and holding the Power and Home buttons.
2. If you have an iPad Pro or an iPad without a Home button, follow Apple's instructions.
3. Open the App Switcher and close the Lockdown Browser app.
4. Restart your iPad to ensure it's completely closed.

https://digitalhow.co.uk/how-to-exit-lockdown-browser-on-ipad/

https://www.solveyourtech.com/how-to-exit-lockdown-browser-on-ipad-a-step-by-step-guide/