Q: iPad doesn't work with lock rotate

Swipe up from the bottom of the screen to bring up the control center. Then tap the icon that looks like a lock inside a circular arrow. If that doesn't work, see if the side switch is controlling rotation. About the iPad Side Switch - Apple Support

-AJ

If the screen is really locked, you will see the padlock icon in the upper right corner of the screen. If you don't see the lock icon, try a forced restart to fix the rotation issue.

To force restart your device, press and hold both the Sleep/Wake and Home buttons for at least ten seconds, until you see the Apple logo.