How can you turn off restrictions?

Did you apply the restrictions - in which case you should know the ScreenTime/Restrictions Passcode - or have the restrictions been applied by someone else (such as a parent, school or employer) that manages your iPad?

If someone else manages your iPad, you’ll need to talk to them.

Otherwise, for a device that is not controlled or managed by someone else - and your have forgotten the ScreenTime/Restrictions Passcode that you have applied yourself - one of the two procedures outlined within this link should resolve the problem:

If you forgot your Screen Time passcode - Apple Support

If your iPad is capable of supporting iPadOS 13.x or later, you should update to the most current version before attempting to resolve a forgotten ScreenTime passcode. The most recent iPadOS updates have introduced a new mechanism whereby a forgotten ScreenTime passcode can be reset without wiping the iPad.

To reset a forgotten ScreenTime passcode on older versions of iOS/iPadOS, the iPad must be reset “as new”, losing all locally stored data. In this situation, you’ll not be able to restore your data from an iCloud or iTunes backup - as the forgotten passcode is integral to the backup:

Restore your iPhone, iPad, or iPod to factory settings - Apple Support

I hope this information is helpful to you in successfully resetting your forgotten passcode.

Settings > Screen Time

if you forgot the password

Forgot my screentime password - Apple Community